A power cycling test method and system for a power conversion module of an energy storage battery

Abstract

The present invention provides a power cycling test method for a power conversion module of an energy storage battery to achieve effective testing of the power conversion module. The method tests the power conversion module through a cyclic test circuit, and the cyclic test circuit includes: a first power conversion module, a second power conversion module, a first battery module, a second battery module, and a controller; the AC sides of the first power conversion module and the second power conversion module are connected through a reactor; the DC side of the first power conversion module is connected to the first battery module through a first interface circuit; the DC side of the second power conversion module is connected to the second battery module through a second interface circuit; the test includes: controlling the current change of the AC sides of the first power conversion module and the second power conversion module through the controller; monitoring the state of the power cycling test, and judging the state of the first power module and / or the second power module according to the current information collected at both ends of the first interface current and / or the current information collected at both ends of the second interface current.

Description

Technical Field

[0001] The present invention belongs to the technical field of electric power, and particularly relates to a power cycle test method and system for a power conversion module of a energy storage battery. Background Art

[0002] With the proposal of the dual-carbon goal, large-scale new energy development will become an inevitable path for building a new power system and achieving the dual-carbon goal in the future. After large-scale new energy is connected to the AC power grid, due to the randomness and volatility of wind energy and solar energy, as well as the characteristics of inertia-free and weak damping of wind power and photovoltaic units, it will cause large power and frequency disturbances to the power grid; in addition, the interaction between the converter and the power grid will lead to emerging stability problems such as broadband oscillations, resulting in unit tripping and even equipment damage, endangering the safe and stable operation of the power grid. To solve the above problems, it has become normal for large-scale new energy power stations to configure large-scale energy storage devices for large-scale new energy development in the future.

[0003] The power conversion module of the energy storage battery is the basic unit of high-power cascaded direct-connected energy storage and network-forming energy storage. Ensuring the reliability of the power conversion module of the energy storage battery is an important factor in ensuring the stability of the power grid. Therefore, there is an urgent need for a solution to effectively test the power conversion module of the energy storage battery. Summary of the Invention

[0004] In order to conduct rated active power and 1.1 times rated active power assessment on the power conversion module of the energy storage battery, the present invention proposes a power cycle test method and system for the power conversion module of the energy storage battery to verify the ability of the power conversion module of the energy storage battery to output voltage and current, the functions and performance of the interface circuit of the power conversion module, and the reliability of the heat dissipation system, etc., so as to lay a technical foundation for the development and testing of high-power cascaded direct-connected energy storage and network-forming energy storage systems.

[0005] The present invention provides a power cycle test method for a power conversion module of an energy storage battery, which tests the power conversion module through a cyclic test circuit. The cyclic test circuit includes: a first power conversion module, a second power conversion module, a first battery module, a second battery module, and a controller;

[0006] The AC sides of the first power conversion module and the second power conversion module are connected through a reactor;

[0007] The DC side of the first power conversion module is connected to the first battery module through a first interface circuit;

[0008] The DC side of the second power conversion module is connected to the second battery module through a second interface circuit;

[0009] Testing the power conversion module through the cyclic test circuit includes:

[0010] Control the current change on the AC side of the first power conversion module and the second power conversion module through a controller;

[0011] Monitor the status of the power cycle test, and judge the status of the first power module and / or the second power module according to the current information at both ends of the first interface current and / or the current information at both ends of the second interface current collected.

[0012] Further, the method includes: synchronously increasing the active current set value on the AC side and the reactive current set value on the AC side with a first step size, and monitoring the drag AC current of the first power conversion module and the second power conversion module. When the drag AC current reaches the rated current of the second power conversion module, stably operate for a first duration, and monitor the current waveform and voltage waveform at both ends of the first interface circuit and / or the current waveform and voltage waveform at both ends of the second interface circuit during the operation;

[0013] The first step size is the forward current amplitude.

[0014] Further, the method includes:

[0015] When there is no abnormality in the current waveform and voltage waveform, continue to gradually increase the active current set value on the AC side and the reactive current set value on the AC side to 1.1 times the rated current with the first step size, then stably operate for a second duration, and monitor the current waveform and voltage waveform at both ends of the first interface circuit and / or the current waveform and voltage waveform at both ends of the second interface circuit during the operation.

[0016] Further, the first step size is 50A;

[0017] The first duration is not less than 10 minutes;

[0018] The second duration is not less than 30 minutes.

[0019] Further, synchronously increase the active current set value on the AC side and the reactive current set value on the AC side with a second step size, and monitor the drag AC current of the first power conversion module and the second power conversion module. When the drag AC current reaches the rated current of the second power conversion module, stably operate for a first duration, and monitor the current waveform and voltage waveform at both ends of the first interface circuit and / or the current waveform and voltage waveform at both ends of the second interface circuit during the operation;

[0020] The second step size is the negative current amplitude.

[0021] Further, the method includes:

[0022] When the current waveform and voltage waveform are normal, continue to gradually increase the active current set value on the AC side and the reactive current set value on the AC side to 1.1 times the rated current at the second step size, then operate stably for the second time period, and monitor the current waveform and voltage waveform at both ends of the first interface circuit and / or the current waveform and voltage waveform at both ends of the second interface circuit during the operation process.

[0023] Further, the second step size is -50A;

[0024] The first time period is not less than 10 minutes;

[0025] The second time period is not less than 30 minutes.

[0026] Further, before the test, control the battery cluster circuit breaker in the battery module to be in the off position, and the disconnect switch and contactor to be in the off position;

[0027] After powering on the cyclic test circuit, set the active current set value and reactive current set value on the AC side to 0;

[0028] Close the disconnect switch and the battery cluster circuit breaker of the battery module in sequence. After the battery module charges the capacitor of the corresponding power conversion module to the specified voltage, the contactor is automatically closed;

[0029] Unlock the two power conversion modules;

[0030] Start to execute the control of the current change on the AC side of the first power conversion module and the second power conversion module.

[0031] Further, input control parameters through the user interface, and the controller connected to the user interface controls the current change on the AC side according to the control parameters;

[0032] Feed back the collected current information to the user interface.

[0033] The present invention also provides an energy storage battery power conversion module power cycling test system, including: a first power conversion module, a second power conversion module, a first battery module, a second battery module, and a controller;

[0034] The AC sides of the first power conversion module and the second power conversion module are connected through a reactor;

[0035] The DC side of the first power conversion module is connected to the first battery module through the first interface circuit;

[0036] The DC side of the second power conversion module is connected to the second battery module through the second interface circuit;

[0037] The controller is connected to the first power conversion module and the second power conversion module.

[0038] The present invention conducts a cyclic test by connecting two battery modules through two power change modules, which can effectively detect the power change modules and ensure the reliability of their actual operation. Through reasonable test steps, the scenarios of the power conversion module operating at different powers are fully tested. The test process is easy to control, and the test results are easy to visually feedback.

[0039] Other features and advantages of the present invention will be described in the following specification, and in part, will become apparent from the specification, or will be understood by implementing the present invention. The objectives and other advantages of the present invention can be achieved and obtained through the structures pointed out in the specification, claims, and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0041] Figure 1 It shows a schematic circuit diagram of a power cycle test system for an energy storage battery power conversion module according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0042] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

[0043] The embodiments of the present invention provide a power cycle test method for an energy storage battery power conversion module. Two energy storage battery power conversion modules (hereinafter referred to as power conversion modules) are respectively connected to their corresponding battery modules, and the two power conversion modules are connected through a reactor to form a cyclic test circuit. The controller controls the given current output to the power conversion module, collects relevant current information of the power conversion module, and determines the performance of the power conversion module according to the collected current information. The controller is connected to the control power supply through a power supply switch.

[0044] Without loss of generality, the power cycle test method for the energy storage battery power conversion module in the embodiments of the present invention can be implemented through a power cycle test system for an energy storage battery power conversion module.

[0045] Such asFigure 1 As shown, the system includes two power conversion modules, namely the first power conversion module (Power Conversion Module 1) and the second power conversion module (Power Conversion Module 2). The two power modules are the same, that is, they have the same specification parameters. Both power conversion modules are connected to the control power supply, and the control power supply is specifically a 220V AC power supply. During testing, the 220V AC power is converted into a 15V DC power supply to provide the control power supply for the power conversion modules. The power supply of the power module is provided by the battery module. The DC output terminals (DC side) of each power conversion module are also respectively connected with interface circuits. Among them, the DC output terminal of the first power conversion module is connected to the first interface circuit (Interface Circuit 1), and the DC output terminal of the second power conversion module is connected to the second interface circuit (Interface Circuit 2); the first power conversion module is connected to the first battery module (Battery Module 1) through the first interface circuit, that is, the first interface circuit is connected between Power Conversion Module 1 and Battery Module 1; the second power conversion module is connected to the second battery module (Battery Module 2) through the second interface circuit, that is, the first interface circuit is connected between Power Conversion Module 2 and Battery Module 2.

[0046] The second power conversion module is connected to the AC side of the first power conversion module through a reactor, and the connection method is the same-name terminal connection. Specifically, the corresponding AC buses in the two power conversion modules are connected through a reactor. Exemplarily, the reactor is specifically an inductor L, and the Hall coil is used as the test current, that is, the sensor for the countercurrent.

[0047] Both the first power conversion module and the second power conversion module are connected to the control chassis (as the controller) through optical fibers. Each power conversion module includes a transmission port XT and a reception port XR, both of which are connected to the control chassis. Among them, the transmission port XT is used to send status information to the control chassis, and the reception port is used to receive the control instructions from the control chassis. The control chassis is connected to the transmission port XT of the second power module through the interface XTA, connected to the reception port XR of the second power module through the interface XRA, connected to the transmission port XT of the first power module through the interface XTB, connected to the reception port XR of the first power module through the interface XRB, and connected to the Hall coil through the Hall interface to collect current information.

[0048] The controller is connected to the 220V AC power supply through the power supply switch K3; the current acquisition device acquires the current at a specified position in the loop test circuit and sends it into the control chassis. Specifically, the current clamp is used as the current acquisition device to acquire the current information between the power conversion module and the corresponding interface circuit (position 1) and the current information between the interface circuit and the battery module (i.e., the current information at both ends of the interface circuit), and sends it into the control chassis. The control chassis is connected to the touch screen through the COM (cluster communication port, serial communication port) port and provides a 24V DC power supply for the touch screen. The magnitude of the AC current is sent down through the touch screen, and the control chassis controls the full load and 1.1 times overload operation of the first power conversion module and the second power conversion module according to the sent-down current magnitude.

[0049] In the test method of the embodiment of the present invention, the controller controls the current change on the AC side of the first power conversion module and the second power conversion module; acquires the current information at both ends of the second interface current, and judges whether the second power conversion module is normal according to the current information.

[0050] The process of controlling the current change includes controlling the current to increase positively and negatively.

[0051] Positive increase: Synchronously increase the active current set value on the AC side and the reactive current set value on the AC side with the first step length, and monitor the drag AC current of the first power conversion module and the second power conversion module. When the drag AC current reaches the rated current of the second power conversion module, stably operate for the first duration, and monitor the current waveform and voltage waveform at both ends of the second interface circuit and the current waveform and voltage waveform at both ends of the first interface circuit during the operation process; the first step length is the positive current amplitude. When there is no abnormality in the current waveform and the low-voltage waveform, continue to gradually increase the active current set value on the AC side and the reactive current set value on the AC side to 1.1 times the rated current with the first step length, and stably operate for the second duration, and monitor the current waveform and voltage waveform at both ends of the second interface circuit during the operation process.

[0052] Reverse increase: Synchronously increase the active current reference value on the AC side and the reactive current reference value on the AC side with the second step size, and monitor the AC current of the back-to-back operation of the first power conversion module and the second power conversion module. When the back-to-back AC current reaches the rated current of the second power conversion module, operate stably for the first duration, and monitor the current waveform and voltage waveform at both ends of the second interface circuit and / or the current waveform and voltage waveform at both ends of the first interface circuit during the operation; the second step size is the negative current amplitude. When there is no abnormality in the current waveform and low voltage waveform, continue to gradually increase the active current reference value on the AC side and the reactive current reference value on the AC side to 1.1 times the rated current with the second step size, operate stably for the second duration, and monitor the current waveform and voltage waveform at both ends of the second interface circuit and / or the current waveform and voltage waveform at both ends of the first interface circuit during the operation.

[0053] Specifically, before performing a cyclic test using the above system (when the power conversion module operates at a certain switching frequency), first wire according to the system structure. When wiring, ensure that the battery cluster circuit breaker QF in the battery module is in the off position, and the disconnect switch and contactor (not shown in the figure) in the battery module are in the off position. The test steps are as follows:

[0054] a) Close the control switch K2 to power on the cyclic test circuit; close the power supply switch K3 of the control chassis, set the switching frequency parameter and modulation ratio parameter of the power module through the touch screen, and set the rated DC voltage of the power conversion module; click on parameter setting on the touch screen and set the active current reference value and reactive current reference value on the AC side to 0;

[0055] b) Close the disconnect switch and the battery cluster circuit breaker QF of the battery module in sequence. The battery module charges the capacitor of the corresponding power conversion module to 1200V, and the contactor is automatically closed;

[0056] c) The touch screen issues an unlock command for Power Conversion Module 1 and Power Conversion Module 2. When the LED5 on the PMC board lights up, it indicates successful unlocking; the power conversion module is converted from the shutdown state to the working state through unlocking.

[0057] d) Click on parameter setting on the touch screen, synchronously increase the active current set value on the AC side and the reactive current set value on the AC side in steps of 50 A, monitor the back-to-back AC current waveforms of the first power conversion module and the second power conversion module through an oscilloscope, and stop when the back-to-back AC current reaches the rated current; record the current value at this time, and monitor the voltage waveforms and current waveforms before and after (at both ends) the interface circuit of the second power conversion module and / or the current waveforms and voltage waveforms at both ends of the first interface circuit; operate for 10 min (or more), if the current waveforms and voltage waveforms are normal, continue to increase the active current set value on the AC side and the reactive current set value on the AC side in steps of 50 A to 1.1 times the rated current, and operate for more than 30 min in this condition, specifically 30 - 40 min, for example 30 min, and observe the current waveforms and voltage models before and after the second interface circuit on the DC side of power conversion module 2 and / or the current waveforms and voltage waveforms at both ends of the first interface circuit;

[0058] e) Click on parameter setting on the touch screen, gradually decrease the active current set value and the reactive current set value on the AC side to 0 with 50 A as the reference;

[0059] f) Click on parameter setting on the touch screen, synchronously increase the active current set value on the AC side and the reactive current set value on the AC side in steps of - 50 A, and at the same time monitor the back-to-back AC current waveforms of the first power conversion module and the second power conversion module through an oscilloscope, and stop when the effective current value reaches about the rated current; record the current value at this time, and monitor the voltage waveforms and current waveforms before and after the interface circuit of the second power conversion module on the DC side of power conversion module 2 and / or the current waveforms and voltage waveforms at both ends of the first interface circuit; operate for 10 min (or more), if there is no abnormality, continue to increase the active current set value and the reactive current set value to 1.1 times the rated current with - 50 A as the reference, and operate for 30 min (or more than 30 min to 40 min) in this condition, monitor the current waveforms and voltage waveforms before and after the interface circuit of the second power conversion module on the DC side of power conversion module 2 and / or the current waveforms and voltage waveforms at both ends of the first interface circuit, and judge whether there is an abnormality. If the waveforms are normal, it means that the power conversion module is normal;

[0060] g) After completing the cyclic test, gradually decrease the current with 50 A as the reference. After the current value reaches 0 A, then sequentially disconnect the battery cluster circuit breaker QF and the disconnecting switch, and wait for the battery module and the power conversion module to discharge;

[0061] h) After the test is completed, use a multimeter to measure the DC input end and the AC output end of the power conversion module under test (the first power conversion module and / or the second power conversion module). Only when there is no voltage can the power conversion module under test be removed.

[0062] Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A power cycling test method for a power conversion module of an energy storage battery, characterized in that, The power conversion module is tested through a cyclic test circuit, and the cyclic test circuit includes: a first power conversion module, a second power conversion module, a first battery module, a second battery module, and a controller; The AC sides of the first power conversion module and the second power conversion module are connected through a reactor; The DC side of the first power conversion module is connected to the first battery module through a first interface circuit; The DC side of the second power conversion module is connected to the second battery module through a second interface circuit; Testing the power conversion module through the cyclic test circuit includes: Controlling the current change of the AC sides of the first power conversion module and the second power conversion module through the controller; Monitoring the state of the power cycle test, and judging the state of the first power module according to the current information collected at both ends of the first interface circuit, and / or judging the state of the second power module according to the current information collected at both ends of the second interface circuit; Before the test, control the battery cluster circuit breaker in the battery module to be in the off position, and the disconnect switch and the contactor to be in the off position; After powering on the cyclic test circuit, set the active current set value and the reactive current set value on the AC side to 0; Close the disconnect switch and the battery cluster circuit breaker of the battery module in sequence. After the battery module charges the capacitor of the corresponding power conversion module to the specified voltage, the contactor is automatically closed; Unlock the two power conversion modules; Start to execute the control of the current change of the AC sides of the first power conversion module and the second power conversion module.

2. The power cycle test method for the energy storage battery power conversion module according to claim 1, characterized in that It includes: Synchronously increasing the active current set value and the reactive current set value on the AC side with the first step length, and monitoring the counter-dragging AC current of the first power conversion module and the second power conversion module. When the counter-dragging AC current reaches the rated current of the second power conversion module, stably operate for the first duration, and monitor the current waveform and voltage waveform at both ends of the first interface circuit and / or the current waveform and voltage waveform at both ends of the second interface circuit during the operation; The first step length is the positive current amplitude.

3. The power cycle test method for the energy storage battery power conversion module according to claim 2, wherein It includes: When there is no abnormality in the current waveform and voltage waveform, continue to gradually increase the active current set value and the reactive current set value on the AC side to 1.1 times the rated current with the first step length, and then stably operate for the second duration, and monitor the current waveform and voltage waveform at both ends of the first interface circuit and / or the current waveform and voltage waveform at both ends of the second interface circuit during the operation.

4. The power cycle test method for the energy storage battery power conversion module according to claim 3, wherein The first step length is 50A; The first duration is not less than 10 minutes; The second duration is not less than 30 minutes.

5. The power cycle test method for the energy storage battery power conversion module according to claim 1, characterized in that Synchronously increasing the active current set value and the reactive current set value on the AC side with the second step length, and monitoring the counter-dragging AC current of the first power conversion module and the second power conversion module. When the counter-dragging AC current reaches the rated current of the second power conversion module, stably operate for the first duration, and monitor the current waveform and voltage waveform at both ends of the first interface circuit and / or the current waveform and voltage waveform at both ends of the second interface circuit during the operation; The second step length is the negative current amplitude.

6. The power cycle test method for the energy storage battery power conversion module according to claim 5, wherein It includes: When there is no abnormality in the current waveform and voltage waveform, continue to gradually increase the active current set value on the AC side and the reactive current set value on the AC side to 1.1 times the rated current at the second step size, and then stably operate for the second time period, and monitor the current waveform and voltage waveform at both ends of the first interface circuit and / or the current waveform and voltage waveform at both ends of the second interface circuit during the operation process.

7. The power cycling test method for an energy storage battery power conversion module according to claim 6, characterized in that the second step size is -50 A; the first time period is not less than 10 minutes; the second time period is not less than 30 minutes.

8. The power cycling test method for an energy storage battery power conversion module according to any one of claims 1-7, characterized in that input control parameters through the user interface, and the controller connected to the user interface controls the current change on the AC side according to the control parameters; Feed back the collected current information to the user interface.

9. A power cycle test system for a power conversion module of an energy storage battery, characterized in that It includes: a first power conversion module, a second power conversion module, a first battery module, a second battery module and a controller; The AC sides of the first power conversion module and the second power conversion module are connected through a reactor; The DC side of the first power conversion module is connected to the first battery module through the first interface circuit; The DC side of the second power conversion module is connected to the second battery module through the second interface circuit; The controller is connected to the first power conversion module and the second power conversion module; The controller is used to judge the state of the first power module according to the current information collected at both ends of the first interface circuit, and / or judge the state of the second power module according to the current information collected at both ends of the second interface circuit; Before the test, the controller is further used to control the battery cluster circuit breaker in the battery module to be in the off position, and the disconnect switch and the contactor to be in the off position; after powering on the cycling test circuit, set the active current set value and the reactive current set value on the AC side to 0; close the disconnect switch and the battery cluster circuit breaker of the battery module in sequence. After the battery module charges the capacitor of the corresponding power conversion module to the specified voltage, the contactor is automatically closed; unlock the two power conversion modules; start to execute the control of the current change on the AC side of the first power conversion module and the second power conversion module.

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