Test platform and test method for bidirectional DC-DC converter for energy storage

Abstract

The embodiment of the present invention provides a test platform and test method for a bidirectional DC-DC converter for energy storage, including a 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 bidirectional DC-DC converter cabinet when it is running in the buck mode and obtains the first test result. During the test, the electric energy obtained from the input power supply by the second PWM rectifier cabinet passes through the 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 solving the assessment test of the large-capacity bidirectional DC-DC converter at the buck under low-loss conditions.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of electrical technology, and in particular to a testing platform and a testing method for a bidirectional DC-DC converter for energy storage. Background Art

[0002] In recent years, bidirectional DC-DC converters have been widely used in the fields of new energy, aerospace, transportation, communications and industrial control. Usually, bidirectional DC-DC converters are used in conjunction with energy storage devices.

[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 supply and load capacity, realizing the assessment and testing of large-capacity bidirectional DC-DC converters during voltage reduction is a problem that needs to be solved urgently by current technicians in this field. Summary of the invention

[0005] The embodiments of the present invention provide a test platform and a test method for a bidirectional DC-DC converter for energy storage, so as to overcome the problem that the prior art cannot implement the assessment test of a large-capacity bidirectional DC-DC converter during voltage reduction under limited power supply and load capacity.

[0006] On the one hand, an embodiment of the present invention provides a test platform for a bidirectional DC-DC converter for energy storage, comprising a 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 bidirectional DC-DC converter cabinet, and the second end of the bidirectional DC-DC converter cabinet is connected to the second end of the first PWM rectifier cabinet;

[0009] The control console is connected to the bidirectional DC-DC converter cabinet, the first PWM rectifier cabinet and the second PWM rectifier cabinet respectively, and is used to control the bidirectional DC-DC converter cabinet to operate in a buck mode, control the second PWM rectifier cabinet to operate in a rectifier mode, control the first PWM rectifier cabinet to operate in an inverter mode, and control the voltage of the second end of the first PWM rectifier cabinet to be maintained within a preset voltage range when operating in the inverter mode;

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

[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 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 bidirectional DC-DC converter cabinet according to the first test parameter includes:

[0016] A first test result of the 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 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.

[0018] Optionally, the bidirectional DC-DC converter cabinet is used to maintain the current value of the second end of the bidirectional DC-DC converter cabinet at a first constant current through a current closed-loop control method.

[0019] Optionally, controlling the first PWM rectifier cabinet to operate in an inverter mode, and controlling the voltage of the second end of the first PWM rectifier cabinet to be maintained within a preset voltage range when operating in the inverter mode, includes:

[0020] Controlling the first PWM rectifier cabinet to operate in an inverter mode, and when operating in the inverter mode, controlling the voltage at the second end of the first PWM rectifier cabinet to increase from a first voltage to a second voltage according to a preset capacitance value and a collected current and an initial voltage at the second end of the first PWM rectifier cabinet, wherein the first voltage and the second voltage are voltages within the preset voltage range;

[0021] The preset voltage range is set according to the test requirements.

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

[0023] Optionally, it also includes:

[0024] The control console is also used to control the bidirectional DC-DC converter cabinet to operate in a boost mode, control the second PWM rectifier cabinet to operate in an inverter mode, control the first PWM rectifier cabinet to operate in a rectifier mode, and control the voltage of the second end of the first PWM rectifier cabinet to be maintained within a preset voltage range when operating in the rectifier mode;

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

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

[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 bidirectional DC-DC converter cabinet, where the second configuration instruction is used to configure the bidirectional DC-DC converter cabinet to operate in a buck mode;

[0029] The control console sends a third configuration instruction to the first PWM rectifier cabinet, where the third configuration instruction is used to configure the first PWM rectifier cabinet to operate in an inverter mode;

[0030] The control console sends a first control instruction to the bidirectional DC-DC converter cabinet, where the first control instruction is used to instruct the bidirectional DC-DC converter cabinet to start operation;

[0031] The control console sends a second control instruction to the first PWM rectifier cabinet, where the second control instruction is used to instruct the first PWM rectifier cabinet to start operation;

[0032] The control console sends a third control instruction to the second PWM rectifier cabinet, wherein the third control instruction is used to instruct the second PWM rectifier cabinet to start operation;

[0033] The console collects a first test parameter of the bidirectional DC-DC converter cabinet when the bidirectional DC-DC converter cabinet operates in a buck mode, and obtains a first test result of the bidirectional DC-DC converter cabinet according to the first test parameter.

[0034] 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 bidirectional DC-DC converter cabinet according to the first test parameter includes:

[0035] A first test result of the 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.

[0036] 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.

[0037] Optionally, the second configuration instruction is further used to configure the bidirectional DC-DC converter cabinet to maintain the current value of the second end of the bidirectional DC-DC converter cabinet at a first constant current through a current closed-loop control method.

[0038] Optionally, before the console collects the first test parameter when the bidirectional DC-DC converter cabinet operates in the buck mode, the control console further includes:

[0039] The control console sends a fourth control instruction to the first PWM rectifier cabinet, wherein the fourth control instruction is used to control the first PWM rectifier cabinet to operate in an inverter mode, and when operating in the inverter mode, according to a preset capacitance value and a collected current and an initial voltage at the second end of the first PWM rectifier cabinet, control the voltage at the second end of the first PWM rectifier cabinet to increase from a first voltage to a second voltage, wherein the first voltage and the second voltage are voltages within the preset voltage range;

[0040] The preset voltage range is set according to the test requirements.

[0041] Optionally, the first voltage is configured by a third configuration instruction, and the third 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 the first voltage through a voltage-current dual closed-loop control method.

[0042] Optionally, 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 a rectifier mode;

[0043] The console sends a fifth configuration instruction to the bidirectional DC-DC converter cabinet, wherein the fifth configuration instruction is used to configure the bidirectional DC-DC converter cabinet to operate in a boost mode;

[0044] The console sends a sixth configuration instruction to the second PWM rectifier cabinet, where the sixth configuration instruction is used to configure the second PWM rectifier cabinet to operate in an inverter mode;

[0045] The control console sends a fifth control instruction to the bidirectional DC-DC converter cabinet, wherein the fifth control instruction is used to instruct the bidirectional DC-DC converter cabinet to start operation;

[0046] The control console sends a sixth control instruction to the second PWM rectifier cabinet, where the sixth control instruction is used to instruct the second PWM rectifier cabinet to start operation;

[0047] The control console sends a seventh control instruction to the first PWM rectifier cabinet, where the seventh control instruction is used to instruct the first PWM rectifier cabinet to start operation;

[0048] The console collects a second test parameter of the bidirectional DC-DC converter cabinet when the bidirectional DC-DC converter cabinet operates in a boost mode, and obtains a second test result of the bidirectional DC-DC converter cabinet according to the second test parameter.

[0049] The embodiment of the present invention provides a test platform and test method for a bidirectional DC-DC converter for energy storage, comprising a 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 controls the bidirectional DC-DC converter cabinet, the first PWM rectifier cabinet and the second PWM rectifier cabinet to operate in different modes, collects a first test parameter when the bidirectional DC-DC converter cabinet operates in a buck mode, and obtains a first test result when the bidirectional DC-DC converter cabinet operates in a buck mode according to the first test parameter. During the test, the electric energy obtained from the input power supply by the second PWM rectifier cabinet passes through the 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 solving the problem of realizing the assessment test of a large-capacity bidirectional DC-DC converter at buck under limited power supply and load capacity. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 A schematic diagram of the structure of a test platform for a bidirectional DC-DC converter for energy storage provided in an embodiment of the present invention;

[0051] Figure 2 It is a schematic diagram of the structure of another test platform for a bidirectional DC-DC converter for energy storage provided by an embodiment of the present invention;

[0052] 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;

[0053] Figure 4 is a circuit diagram of a current closed-loop control method provided by an embodiment of the present invention;

[0054] Figure 5 It is a flow chart of a testing method for a bidirectional DC-DC converter for energy storage provided by an embodiment of the present invention;

[0055] Figure 6 It is a flowchart of another method for testing a bidirectional DC-DC converter for energy storage provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0056] 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.

[0057] The technical solution of the embodiment of the present invention will be described below in conjunction with several specific embodiments.

[0058] Figure 1 A schematic diagram of a test platform structure for a bidirectional DC-DC converter for energy storage provided by an embodiment of the present invention, such as Figure 1 As shown, it includes a bidirectional DC-DC converter cabinet 1, a first PWM rectifier cabinet 2, a second PWM rectifier cabinet 3, a control console 4 and an input power supply 5.

[0059] The input power source 5 is connected 31 to the first end 21 of the first PWM rectifier cabinet 2 and the first end of the second PWM rectifier cabinet 3 , respectively.

[0060] The second end 32 of the second PWM rectifier cabinet 3 is connected to the first end 11 of the bidirectional DC-DC converter cabinet 1 , and the second end 12 of the bidirectional DC-DC converter cabinet 1 is connected to the second end 22 of the first PWM rectifier cabinet 2 .

[0061] The console 4 is respectively connected to the bidirectional DC-DC converter cabinet 1, the first PWM rectifier cabinet 1 and the second PWM rectifier cabinet 1. The console 1 is used to control the bidirectional DC-DC converter cabinet 1 to operate in the buck mode, control the second PWM rectifier cabinet 3 to operate in the rectifier mode, control the first PWM rectifier cabinet 2 to operate in the inverter mode, and control the voltage of the second end 22 of the first PWM rectifier cabinet 2 to be maintained within a preset voltage range when operating in the inverter mode.

[0062] The console 4 is also used to collect a first test parameter of the bidirectional DC-DC converter cabinet 1 when it operates in the buck mode, and obtain a first test result of the bidirectional DC-DC converter cabinet 1 according to the first test parameter.

[0063] In this embodiment, the input power source refers to an AC power source, which may be a low-voltage power grid, and the input voltage is 380V and the frequency is 50Hz.

[0064] Among them, the control console controls the bidirectional DC-DC converter cabinet, the second PWM rectifier cabinet and the first PWM rectifier cabinet to operate in buck mode, rectification mode and inverter mode respectively. Buck mode refers to the mode of converting a higher DC voltage to a required lower DC voltage, and the corresponding boost mode refers to the mode of converting a lower DC voltage to a required higher DC voltage; the bidirectional DC-DC converter operating in boost mode or buck mode is the basic function of the bidirectional DC-DC converter. Rectification mode refers to the process of converting AC power to DC power as rectification mode; inverter mode corresponds to rectification mode, which means that the process of converting DC power to AC power is inverter mode.

[0065] 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 bidirectional DC-DC converter cabinet operates in the step-down mode, converting the DC voltage V1 into a voltage range X, where the voltage values ​​in X are all less than V1; 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 bidirectional DC-DC converter cabinet when stepping down by collecting the first test parameter of the bidirectional DC-DC converter cabinet. At the same time, the electric energy obtained by the second PWM rectifier cabinet from the input power supply passes through the bidirectional DC-DC converter cabinet, and then passes through the first PWM rectifier cabinet to feed back to the input power supply. The obtained electric energy and the fed-back electric energy offset each other, reducing the requirements for the power grid capacity. Therefore, this embodiment solves the problem of realizing the assessment test of a large-capacity bidirectional DC-DC converter when stepping down under limited power supply and load capacity.

[0066] Figure 2 FIG. 1 is a schematic diagram of a test platform structure of another bidirectional DC-DC converter for energy storage provided by an embodiment of the present invention. Figure 2 As shown, including:

[0067] The input power supply 5 includes a low-voltage power grid 51 , a low-voltage power distribution cabinet 52 and an isolation transformer 53 . The input power supply 5 is used to provide power to the first PWM rectifier cabinet 2 and the second PWM rectifier cabinet 3 .

[0068] 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.

[0069] Optionally, the isolation transformer is a three-winding transformer.

[0070] The input power source 5 is connected to the first end 21 of the first PWM rectifier cabinet 2 and the first end 31 of the second PWM rectifier cabinet 3 respectively, including:

[0071] The first end 21 of the first PWM rectifier cabinet 2 and the first end 31 of the second PWM rectifier cabinet 3 are respectively connected to two windings on the secondary side of the isolation transformer 53 .

[0072] 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 21 of the first PWM rectifier cabinet 2 and the first end 31 of the second PWM rectifier cabinet 3.

[0073] Optionally, the bidirectional DC-DC converter cabinet includes a bidirectional DC-DC converter and a 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 console is respectively connected to the bidirectional DC-DC converter cabinet, the first PWM rectifier cabinet and the second PWM rectifier cabinet, including:

[0074] The control console is respectively connected with the bidirectional DC-DC controller, the first PWM controller and the second PWM controller.

[0075] Optionally, the control console is a personal computer (PC), and the PC is respectively connected to the bidirectional DC-DC converter cabinet, the first PWM rectifier cabinet, and the second PWM rectifier cabinet.

[0076] 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 bidirectional DC-DC converter cabinet 1 according to the first test parameter includes:

[0077] A first test result of the bidirectional DC-DC converter cabinet 1 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.

[0078] 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:

[0079] P(t)=u(t)×i(t) (1)

[0080] Wherein, when stepping down, 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.

[0081] 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:

[0082]

[0083] Among them, E in Input power to the 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.

[0084] 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:

[0085]

[0086] 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.

[0087] 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:

[0088]

[0089] 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.

[0090] The first ambient temperature assessment result in the first test result is obtained in the following way:

[0091] The ambient temperature assessment result during the pressure increase is obtained according to the first ambient temperature.

[0092] Through the above calculation method, the first test result of the bidirectional DC-DC converter cabinet during voltage reduction can be obtained.

[0093] Optionally, the second PWM rectifier cabinet 3 is used to maintain the voltage value of the second end 32 of the second PWM rectifier cabinet 3 at a first constant voltage through a voltage and current dual closed-loop control method.

[0094] 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.

[0095] Optionally, the bidirectional DC-DC converter cabinet 1 is used to maintain the current value of the second end 12 of the bidirectional DC-DC converter cabinet 1 at a first constant current through a current closed-loop control method.

[0096] The current closed-loop control method is used to control the current at the second end 12 of the 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.

[0097] Optionally, controlling the first PWM rectifier cabinet 2 to operate in the inverter mode, and controlling the voltage of the second end 22 of the first PWM rectifier cabinet 2 to maintain within a preset voltage range when operating in the inverter mode, includes:

[0098] Controlling the first PWM rectifier cabinet to operate in an inverter mode, and when operating in the inverter mode, controlling the voltage at the second end of the first PWM rectifier cabinet to increase from a first voltage to a second voltage according to a preset capacitance value and a collected current and an initial voltage at the second end of the first PWM rectifier cabinet, wherein the first voltage and the second voltage are voltages within a preset voltage range;

[0099] The preset voltage range is set according to the test requirements.

[0100] Generally, for the test of bidirectional DC-DC converter cabinet, it is necessary to connect a supercapacitor at the rear end of the bidirectional DC-DC converter cabinet, and set multiple capacitance values ​​of the supercapacitor to meet the test parameters of the bidirectional DC-DC converter cabinet at different capacitance values. For example, when the capacitance value is C1, it is necessary to test the test parameters of the bidirectional DC-DC converter cabinet when the terminal voltage of the supercapacitor is charged and discharged within the preset range; when the capacitance value is C2, it is necessary to test the test parameters of the bidirectional DC-DC converter cabinet when the terminal voltage of the supercapacitor is charged and discharged within the preset range.

[0101] In this embodiment, the first PWM rectifier cabinet is used to simulate a supercapacitor, and the preset voltage at the second end of the first PWM rectifier cabinet is used for the terminal voltage of the simulated supercapacitor. In this embodiment, by setting the capacitance value C of the simulated supercapacitor and the collected current and initial voltage at the second end of the first PWM rectifier cabinet, the preset voltage at the second end of the first PWM rectifier cabinet at time t is calculated, and the calculation formula (5) is as follows:

[0102]

[0103] Wherein U(t) is the preset voltage of the second end at time t, that is, the terminal voltage of the simulated supercapacitor, C is the preset capacitance value of the simulated supercapacitor, U(t0) is the initial voltage of the simulated supercapacitor, and i(t) is the collected current of the second end of the first PWM rectifier cabinet at time t.

[0104] After the capacitance value of the simulated supercapacitor is given, the voltage value (voltage value increase) of the terminal voltage of the supercapacitor with the capacitance value when charging or discharging (here charging) can be calculated by the above formula (5), and the terminal voltage change of the supercapacitor is simulated by controlling the voltage of the second terminal of the first PWM rectifier cabinet in real time to follow the above voltage value that changes with time. The terminal voltage of the simulated supercapacitor should be within a preset range.

[0105] For example, given that the capacitance value of the supercapacitor to be tested is C1, the test result of the bidirectional DC-DC converter cabinet is tested. By simulating the capacitance value C1 of the supercapacitor and the collected current and initial voltage of the second end of the first PWM rectifier cabinet as the lower limit X1 of the voltage range X, the terminal voltage value of the supercapacitor at time t can be calculated as U(t), and by real-time controlling the voltage of the second end of the first PWM rectifier cabinet to be U(t), the terminal voltage of the supercapacitor is simulated to increase to the upper limit X2 of the voltage range X over time. At this time, by collecting the test parameters of the bidirectional DC-DC converter cabinet, the test result of the bidirectional DC-DC converter cabinet is further obtained when the capacitance value of the supercapacitor is C1 and the voltage variation range is X.

[0106] This embodiment can simulate a supercapacitor of any capacity through the above method, thus broadening the test range.

[0107] Optionally, the first PWM rectifier cabinet is used to maintain the voltage value of the second end 22 of the first PWM rectifier cabinet 2 within a preset voltage range through a voltage and current dual closed-loop control method.

[0108] The voltage and current double closed-loop control mode is used to control the voltage of the second end 22 of the first PWM rectifier cabinet 2 to be constant within a preset voltage range. The voltage and current double closed-loop control mode is the same as that of the second PWM rectifier cabinet, and will not be repeated here.

[0109] Previous Figure 1 The bidirectional DC-DC converter cabinet 1 operates in the buck mode, the second PWM rectifier cabinet 3 operates in the rectifier mode, and the first PWM rectifier cabinet 2 operates in the inverter mode. In an optional implementation, it also includes:

[0110] The console 4 is also used to control the bidirectional DC-DC converter cabinet 1 to operate in the boost mode, control the second PWM rectifier cabinet 3 to operate in the inverter mode, control the first PWM rectifier cabinet 2 to operate in the rectification mode, and control the voltage of the second end 22 of the first PWM rectifier cabinet 2 to be maintained within a preset voltage range when operating in the rectification mode.

[0111] The console is also used to collect a second test parameter of the bidirectional DC-DC converter cabinet 1 when it operates in the boost mode, and obtain a second test result of the bidirectional DC-DC converter cabinet 1 according to the second test parameter.

[0112] The current flow process is as follows: first, the first PWM rectifier cabinet operates in the rectifier mode to convert the AC power of the input power supply into DC power, and the DC voltage is within the preset voltage range X; second, the bidirectional DC-DC converter cabinet operates in the boost mode to increase the DC voltage to the DC voltage V2, where V2 is greater than any voltage value in X; finally, the second PWM rectifier cabinet operates in the inverter mode to convert the DC power into AC power and feed it back to the AC power grid. The console further obtains the second test result of the bidirectional DC-DC converter cabinet when boosting by collecting the test parameters of the bidirectional DC-DC converter cabinet. This embodiment, combined with the first test result, can obtain the comprehensive test results of the bidirectional DC-DC converter cabinet when boosting and reducing the voltage.

[0113] This embodiment can obtain comprehensive test results of the bidirectional DC-DC converter cabinet during boost and buck through a single test process, thereby solving the problem of implementing assessment tests of large-capacity bidirectional DC-DC converters during boost and buck under limited power and load capacity.

[0114] 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 a second test result of the bidirectional DC-DC converter cabinet 1 is obtained according to the second test parameters, including:

[0115] A second test result of the 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.

[0116] 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 bidirectional DC-DC converter cabinet is running in the buck mode, while the second test parameters are the parameters collected when the bidirectional DC-DC converter cabinet is running in the boost 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.

[0117] The second test result of the bidirectional DC-DC converter cabinet during voltage boosting can be obtained by the same calculation method as the first test result.

[0118] Optionally, the second PWM rectifier cabinet 3 is used to maintain the voltage value of the second end 32 of the second PWM rectifier cabinet 3 at a second constant voltage through a voltage and current dual closed-loop control method.

[0119] The second constant voltage may be the same as or different from the first constant voltage.

[0120] Optionally, the bidirectional DC-DC converter cabinet 1 is used to maintain the current value of the second end 12 of the bidirectional DC-DC converter cabinet 1 at a second constant current through a current closed-loop control method.

[0121] The second constant current may be the same as or different from the first constant current.

[0122] Optionally, controlling the first PWM rectifier cabinet 2 to operate in the rectifier mode, and controlling the voltage of the second end 22 of the first PWM rectifier cabinet 2 to maintain within a preset voltage range when operating in the rectifier mode, includes:

[0123] Controlling the first PWM rectifier cabinet to operate in a rectifier mode, and when operating in the rectifier mode, controlling the voltage at the second end of the first PWM rectifier cabinet to decrease from the second voltage to the first voltage according to a preset capacitance value and the collected current and the initial voltage at the second end of the first PWM rectifier cabinet, wherein the first voltage and the second voltage are voltages within a preset voltage range;

[0124] The preset voltage range is set according to the test requirements.

[0125] This embodiment is the same as the above-mentioned first PWM rectifier cabinet operating in the inverter mode, controlling the voltage of the second end of the first PWM rectifier cabinet to maintain within a preset voltage range, which will not be repeated here. The difference is that the above process simulates the charging process of the supercapacitor, and the voltage of the second end of the first PWM rectifier cabinet increases over time, while this embodiment simulates the discharging process of the supercapacitor, and the voltage of the second end of the first PWM rectifier cabinet decreases over time.

[0126] This embodiment can simulate a supercapacitor of any capacity through the above method, thus broadening the test range.

[0127] Optionally, the first PWM rectifier cabinet is used to maintain the voltage value of the second end 22 of the first PWM rectifier cabinet 2 within a preset voltage range through a voltage and current dual closed-loop control method.

[0128] The voltage and current double closed-loop control mode is used to control the voltage of the second end 22 of the first PWM rectifier cabinet 2 to be constant within a preset voltage range. The voltage and current double closed-loop control mode is the same as that of the second PWM rectifier cabinet, and will not be repeated here.

[0129] Figure 5 FIG. 1 is a flow chart of a testing method for a bidirectional DC-DC converter for energy storage provided by an embodiment of the present invention. Figure 5 As shown, the method is applied to a test platform of a bidirectional DC-DC converter for energy storage, the platform comprising a bidirectional DC-DC converter cabinet 1, a first PWM rectifier cabinet 2, a second PWM rectifier cabinet 3, a control console 4 and an input power supply 5, the method comprising:

[0130] S101, the control console 4 sends a first configuration instruction to the second PWM rectifier cabinet 3, where the first configuration instruction is used to configure the second PWM rectifier cabinet 3 to operate in a rectifier mode.

[0131] S102, the control console 4 sends a second configuration instruction to the bidirectional DC-DC converter cabinet 1, where the second configuration instruction is used to configure the bidirectional DC-DC converter cabinet 1 to operate in the buck mode.

[0132] S103, the control console 4 sends a third configuration instruction to the first PWM rectifier cabinet 2, where the third configuration instruction is used to configure the first PWM rectifier cabinet 2 to operate in the inverter mode.

[0133] S104, the control console 4 sends a first control instruction to the bidirectional DC-DC converter cabinet 1, where the first control instruction is used to instruct the bidirectional DC-DC converter cabinet 1 to start running.

[0134] S105: The control console 4 sends a second control instruction to the first PWM rectifier cabinet 2, where the second control instruction is used to instruct the first PWM rectifier cabinet 2 to start operation.

[0135] S106, the control console 4 sends a third control instruction to the second PWM rectifier cabinet 3, where the third control instruction is used to instruct the second PWM rectifier cabinet 3 to start running.

[0136] S107, the console 4 collects a first test parameter of the bidirectional DC-DC converter cabinet 1 when the bidirectional DC-DC converter cabinet 1 operates in the buck mode, and obtains a first test result of the bidirectional DC-DC converter cabinet 1 according to the first test parameter.

[0137] 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.

[0138] The output voltage of the second end of the bidirectional DC-DC converter cabinet is determined by the first PWM rectifier cabinet. In step S103, the third configuration command instructs the first PWM rectifier cabinet to adopt a voltage-current dual closed-loop control method, and inputs a preset output voltage into the voltage-current dual closed-loop control circuit. After adjustment, the second end of the first PWM rectifier cabinet outputs a DC voltage, and the voltage value is within a preset voltage range X. Since the second end of the first PWM rectifier cabinet is connected to the second end of the bidirectional DC-DC converter, the voltage of the second end of the bidirectional DC-DC converter is also X, and the voltage values ​​in X are all less than V1, that is, it operates in step-down mode.

[0139] At the same time, in step S102, the second configuration command instructs the bidirectional DC-DC converter cabinet to adopt a current closed-loop control method, inputs a preset output current into the current dual closed-loop control circuit, and after adjustment, the bidirectional DC-DC converter cabinet outputs a constant current, and through the constant current and X, controls the system power.

[0140] The execution order of steps S101-S103 can be interchanged arbitrarily or can be executed simultaneously.

[0141] Steps S104-S105 may be executed in any order or simultaneously.

[0142] 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 bidirectional DC-DC converter cabinet operates in the step-down mode, converting the DC voltage V1 into a voltage range X, where the voltage values ​​in X are all less than V1; 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 bidirectional DC-DC converter cabinet when stepping down by collecting the first test parameter of the bidirectional DC-DC converter cabinet. At the same time, the electric energy obtained by the second PWM rectifier cabinet from the input power supply passes through the bidirectional DC-DC converter cabinet, and then passes through the first PWM rectifier cabinet to feed back to the input power supply. The obtained electric energy and the fed-back electric energy offset each other. Therefore, this embodiment solves the problem of realizing the assessment test of a large-capacity bidirectional DC-DC converter when stepping down under limited power supply and load capacity.

[0143] 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 bidirectional DC-DC converter cabinet 1 according to the first test parameter includes:

[0144] A first test result of the bidirectional DC-DC converter cabinet 1 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.

[0145] 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.

[0146] By using the above-mentioned calculation method of the first test result, the first test result of the bidirectional DC-DC converter cabinet during voltage reduction can be obtained.

[0147] Optionally, the first configuration instruction is further used to configure the second PWM rectifier cabinet 3 to maintain the voltage value of the second end 32 of the second PWM rectifier cabinet 3 at a first constant voltage through a voltage-current dual closed-loop control method.

[0148] The voltage-current dual closed-loop control mode is used to control the voltage of the second end 32 of the second PWM rectifier cabinet 3 to be constant. The voltage-current dual closed-loop control mode is the same as that of the aforementioned second PWM rectifier cabinet, and will not be described in detail.

[0149] Optionally, the second configuration instruction is further used to configure the bidirectional DC-DC converter cabinet 1 to maintain the current value of the second end 12 of the bidirectional DC-DC converter cabinet 1 at a first constant current through a current closed-loop control method.

[0150] The current closed-loop control method is used to control the current of the second end 12 of the bidirectional DC-DC converter cabinet 1 to be constant. The current closed-loop control method is the same as that of the aforementioned bidirectional DC-DC converter cabinet, and will not be described in detail.

[0151] Optionally, before the console collects the first test parameter when the bidirectional DC-DC converter cabinet operates in the buck mode, the control console further includes:

[0152] S108, the control console sends a fourth control instruction to the first PWM rectifier cabinet, where the fourth control instruction is used to control the first PWM rectifier cabinet to operate in the inverter mode, and when operating in the inverter mode, according to a preset capacitance value and a collected current and an initial voltage at the second end of the first PWM rectifier cabinet, control the voltage at the second end of the first PWM rectifier cabinet to increase from a first voltage to a second voltage, where the first voltage and the second voltage are voltages within a preset voltage range;

[0153] The preset voltage range is set according to the test requirements.

[0154] In a possible implementation manner, the first voltage is a lowest voltage in a preset voltage range, the second voltage is a highest voltage in the preset voltage range, and the initial voltage is the first voltage.

[0155] In another possible implementation, the first voltage and the second voltage are within a preset voltage range but not at an end point of the preset voltage range, and the initial voltage is the first voltage.

[0156] The present embodiment has the same principle as the above-mentioned control of the first PWM rectifier cabinet to operate in the inverter mode, and control of maintaining the voltage of the second end of the first PWM rectifier cabinet within a preset voltage range when operating in the inverter mode, which will not be described in detail here.

[0157] Optionally, the first voltage is configured by a third configuration instruction, and the third 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 the first voltage through a voltage and current dual closed-loop control method.

[0158] The voltage-current dual closed-loop control mode is used to control the voltage of the second end 22 of the first PWM rectifier cabinet 2 to be constant at the first voltage. 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.

[0159] Figure 6 FIG. 1 is a flow chart of another method for testing a bidirectional DC-DC converter for energy storage provided by an embodiment of the present invention. Figure 5 On the basis of Figure 6 As shown, it also includes:

[0160] S201, the control console 4 sends a fourth configuration instruction to the first PWM rectifier cabinet 2, where the fourth configuration instruction is used to configure the first PWM rectifier cabinet 2 to operate in a rectifier mode.

[0161] S202: The control console 4 sends a fifth configuration instruction to the bidirectional DC-DC converter cabinet 1, where the fifth configuration instruction is used to configure the bidirectional DC-DC converter cabinet 1 to operate in a boost mode.

[0162] S203, the control console 4 sends a sixth configuration instruction to the second PWM rectifier cabinet 3, where the sixth configuration instruction is used to configure the second PWM rectifier cabinet 3 to operate in the inverter mode.

[0163] S204, the control console 4 sends a fifth control instruction to the bidirectional DC-DC converter cabinet 1, where the fifth control instruction is used to instruct the bidirectional DC-DC converter cabinet 1 to start running.

[0164] S205: The control console 4 sends a sixth control instruction to the second PWM rectifier cabinet 3, where the sixth control instruction is used to instruct the second PWM rectifier cabinet 3 to start running.

[0165] S206 The control console 4 sends a seventh control instruction to the first PWM rectifier cabinet 2 , where the seventh control instruction is used to instruct the first PWM rectifier cabinet 2 to start operation.

[0166] S207, the console 4 collects a second test parameter of the bidirectional DC-DC converter cabinet 1 when it operates in the boost mode, and obtains a second test result of the bidirectional DC-DC converter cabinet 1 according to the second test parameter.

[0167] In step S201, the fourth configuration command instructs the first PWM rectifier cabinet to adopt a voltage-current dual closed-loop control method, inputs a preset output voltage 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, and the voltage value is within a preset voltage range X.

[0168] The output voltage of the second end of the bidirectional DC-DC converter cabinet is determined by the second PWM rectifier cabinet. In step S203, the sixth configuration command instructs the second PWM rectifier cabinet to adopt a voltage-current dual closed-loop control method, and inputs a preset output voltage into the voltage-current dual closed-loop control circuit. After adjustment, the second end of the second PWM rectifier cabinet outputs a DC voltage V2. Since the second end of the second PWM rectifier cabinet is connected to the second end of the bidirectional DC-DC converter, the voltage of the second end of the bidirectional DC-DC converter is also V2. V2 is greater than any voltage value in X, that is, it operates in boost mode.

[0169] At the same time, in step S202, the fifth configuration command instructs the bidirectional DC-DC converter cabinet to adopt a current closed-loop control method, inputs the preset output current into the current dual closed-loop control circuit, and after adjustment, the bidirectional DC-DC converter cabinet outputs a constant current, and through the constant current and X, controls the system power.

[0170] The execution order of steps S201-S203 may be interchanged arbitrarily or executed simultaneously.

[0171] Steps S204-S205 may be executed in any order or simultaneously.

[0172] The current flow process is as follows: first, the first PWM rectifier cabinet operates in the rectifier mode to convert the AC power of the input power supply into DC power, and the DC voltage is within the preset voltage range X; second, the bidirectional DC-DC converter cabinet operates in the boost mode to increase the DC voltage to the DC voltage V2, where V2 is greater than any voltage value in X; finally, the second PWM rectifier cabinet operates in the inverter mode to convert the DC power into AC power and feed it back to the AC power grid. The console further obtains the second test result of the bidirectional DC-DC converter cabinet when boosting by collecting the test parameters of the bidirectional DC-DC converter cabinet. This embodiment, combined with the first test result, can obtain the comprehensive test results of the bidirectional DC-DC converter cabinet when boosting and reducing the voltage.

[0173] This embodiment can obtain comprehensive test results of the bidirectional DC-DC converter cabinet during boost and buck through a single test process, thereby solving the problem of implementing assessment tests of large-capacity bidirectional DC-DC converters during boost and buck under limited power and load capacity.

[0174] 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 a second test result of the bidirectional DC-DC converter cabinet 1 is obtained according to the second test parameters, including:

[0175] A second test result of the 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.

[0176] 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 bidirectional DC-DC converter cabinet is running in the buck mode, while the second test parameters are the parameters collected when the bidirectional DC-DC converter cabinet is running in the boost 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.

[0177] The second test result of the bidirectional DC-DC converter cabinet during voltage boosting can be obtained by the same calculation method as the first test result.

[0178] Optionally, the second PWM rectifier cabinet 3 is used to maintain the voltage value of the second end 32 of the second PWM rectifier cabinet 3 at a second constant voltage through a voltage and current dual closed-loop control method.

[0179] The second constant voltage may be the same as or different from the first constant voltage.

[0180] Optionally, the bidirectional DC-DC converter cabinet 1 is used to maintain the current value of the second end 12 of the bidirectional DC-DC converter cabinet 1 at a second constant current through a current closed-loop control method.

[0181] The second constant current may be the same as or different from the first constant current.

[0182] Optionally, before the console collects the second test parameter when the bidirectional DC-DC converter cabinet operates in the boost mode, the method further includes:

[0183] S208, the control console sends an eighth control instruction to the first PWM rectifier cabinet, where the eighth control instruction is used to control the first PWM rectifier cabinet to operate in the rectifier mode, and when operating in the rectifier mode, according to a preset capacitance value and a collected current and an initial voltage at the second end of the first PWM rectifier cabinet, control the voltage at the second end of the first PWM rectifier cabinet to decrease from the second voltage to the first voltage, where the first voltage and the second voltage are voltages within a preset voltage range;

[0184] The preset voltage range is set according to the test requirements.

[0185] In a possible implementation, the first voltage is a lowest voltage in a preset voltage range, the second voltage is a highest voltage in the preset voltage range, and the initial voltage is the second voltage.

[0186] In another possible implementation, the first voltage and the second voltage are within a preset voltage range but not at an end point of the preset voltage range, and the initial voltage is the second voltage.

[0187] This embodiment is the same as the above-mentioned first PWM rectifier cabinet operating in the inverter mode, controlling the voltage of the second end of the first PWM rectifier cabinet to maintain within a preset voltage range, which will not be repeated here. The difference is that the above process simulates the charging process of the supercapacitor, and the voltage of the second end of the first PWM rectifier cabinet increases over time, while this embodiment simulates the discharging process of the supercapacitor, and the voltage of the second end of the first PWM rectifier cabinet decreases over time.

[0188] Optionally, the second voltage is configured by a fourth configuration instruction, and 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 the second voltage through a voltage and current dual closed-loop control method.

[0189] The voltage-current dual closed-loop control mode is used to control the voltage of the second end 22 of the first PWM rectifier cabinet 2 to be constant at a second voltage. 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.

[0190] 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.

[0191] 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 test platform for a bidirectional DC-DC converter for energy storage, characterized in that: It includes a 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 bidirectional DC-DC converter cabinet, and the second end of the bidirectional DC-DC converter cabinet is connected to the second end of the first PWM rectifier cabinet; The control console is connected to the bidirectional DC-DC converter cabinet, the first PWM rectifier cabinet and the second PWM rectifier cabinet respectively, and is used to control the bidirectional DC-DC converter cabinet to operate in a buck mode, control the second PWM rectifier cabinet to operate in a rectifier mode, control the first PWM rectifier cabinet to operate in an inverter mode, and control the voltage of the second end of the first PWM rectifier cabinet to be maintained within a preset voltage range when operating in the inverter mode; The console is also used to collect a first test parameter of the bidirectional DC-DC converter cabinet when the cabinet is running in the buck mode, and obtain a first test result of the bidirectional DC-DC converter cabinet according to the first 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 bidirectional DC-DC converter cabinet is used to maintain the current value of the second end of the bidirectional DC-DC converter cabinet at a first constant current through a current 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 bidirectional DC-DC converter cabinet according to the first test parameters includes: A first test result of the 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 controlling the first PWM rectifier cabinet to operate in an inverter mode, and controlling the voltage of the second end of the first PWM rectifier cabinet to be maintained within a preset voltage range when operating in the inverter mode, includes: Controlling the first PWM rectifier cabinet to operate in an inverter mode, and when operating in the inverter mode, controlling the voltage at the second end of the first PWM rectifier cabinet to increase from a first voltage to a second voltage according to a preset capacitance value and a collected current and an initial voltage at the second end of the first PWM rectifier cabinet, wherein the first voltage and the second voltage are voltages within the preset voltage range; The preset voltage range is set according to the test requirements.

6. The test platform according to claim 5, 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 within the preset voltage range through a voltage and current dual closed-loop control method.

7. The test platform according to any one of claims 1 to 6, characterized in that: Also includes: The control console is also used to control the bidirectional DC-DC converter cabinet to operate in a boost mode, control the second PWM rectifier cabinet to operate in an inverter mode, control the first PWM rectifier cabinet to operate in a rectifier mode, and control the voltage of the second end of the first PWM rectifier cabinet to be maintained within a preset voltage range when operating in the rectifier mode; The console is also used to collect a second test parameter of the bidirectional DC-DC converter cabinet when the cabinet is running in a boost mode, and obtain a second test result of the bidirectional DC-DC converter cabinet according to the second test parameter.

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

9. The testing method according to claim 8, 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 bidirectional DC-DC converter cabinet according to the first test parameters includes: A first test result of the 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.

10. The testing method according to claim 8, characterized in that: Before the console collects the first test parameter of the bidirectional DC-DC converter cabinet when operating in the buck mode, the control console also includes: The control console sends a fourth control instruction to the first PWM rectifier cabinet, wherein the fourth control instruction is used to control the first PWM rectifier cabinet to operate in an inverter mode, and when operating in the inverter mode, according to a preset capacitance value and a collected current and an initial voltage at the second end of the first PWM rectifier cabinet, control the voltage at the second end of the first PWM rectifier cabinet to increase from a first voltage to a second voltage, wherein the first voltage and the second voltage are voltages within the preset voltage range; The preset voltage range is set according to the test requirements.

11. The testing method according to claim 10, characterized in that: The first voltage is configured by a third configuration instruction, and the third configuration instruction is also used to configure the first PWM rectifier cabinet to maintain the voltage value of the second end of the first PWM rectifier cabinet at the first voltage through a voltage-current dual closed-loop control method.

12. The testing method according to any one of claims 8 to 11, characterized in that: 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 a rectifier mode; The console sends a fifth configuration instruction to the bidirectional DC-DC converter cabinet, wherein the fifth configuration instruction is used to configure the bidirectional DC-DC converter cabinet to operate in a boost mode; The console sends a sixth configuration instruction to the second PWM rectifier cabinet, where the sixth configuration instruction is used to configure the second PWM rectifier cabinet to operate in an inverter mode; The control console sends a fifth control instruction to the bidirectional DC-DC converter cabinet, wherein the fifth control instruction is used to instruct the bidirectional DC-DC converter cabinet to start operation; The control console sends a sixth control instruction to the second PWM rectifier cabinet, where the sixth control instruction is used to instruct the second PWM rectifier cabinet to start operation; The control console sends a seventh control instruction to the first PWM rectifier cabinet, where the seventh control instruction is used to instruct the first PWM rectifier cabinet to start operation; The console collects a second test parameter of the bidirectional DC-DC converter cabinet when the bidirectional DC-DC converter cabinet operates in a boost mode, and obtains a second test result of the bidirectional DC-DC converter cabinet according to the second test parameter.

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