Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, it will be appreciated by those of ordinary skill in the art that numerous technical details are set forth in order to provide a better understanding of the present application in various embodiments of the present invention. However, the technical solution claimed in the present application can be implemented without these technical details and various changes and modifications based on the following embodiments. The following embodiments are divided for convenience of description, and should not constitute any limitation to the specific implementation of the present invention, and the embodiments may be mutually incorporated and referred to without contradiction.
A first embodiment of the present invention relates to a current transformer detection platform, as shown in fig. 1, specifically including: the device comprises a battery simulation device 101, a converter to be tested 102, a measuring device 103, a power grid simulation device 104, a power grid fault simulation generation device 105, a power supply device 106, an anti-islanding RLC device 107, a first isolation transformer 108, a second isolation transformer 109, a first switch S1, a second switch S2, a third switch S3 and a fourth switch S4; the input end of the battery simulation device 101 is connected with the direct current end of the converter to be tested 102 through a first switch S1; the alternating current end of the converter to be tested 102 is connected with the output end of the power grid simulation device 104 or the output end of the power grid fault simulation generation device 105 through a second switch S2, wherein the second switch S2 is a selection switch; two ends of the measuring device 103 are respectively connected with the direct current end and the alternating current end of the converter 102, and alternating current and direct current performance parameter data of the converter 102 to be measured are collected; the two ends of the grid simulator 104 form a loop through a third switch S3, wherein the third switch S3 controls the operation of the grid simulator 104; the input end of the power grid simulation device is connected with the power supply device 106 through a first isolation transformer 108, and the input end of the power grid fault simulation device is connected with the power supply device 106 through a second isolation transformer 109; the anti-islanding RLC device 107 is connected to the detection platform through the fourth switch S4, wherein an access point of the anti-islanding RLC device 107 is located between the second switch S2 and the grid simulation device 104. The input terminal of the battery simulator 101 is connected to the dc terminal of the converter 102 via the first switch S1.
Specifically, the battery simulator 101 has high precision and high dynamic response characteristics, adopts full digital control, has high control precision, high response speed, wide output regulation range, and has the function of feeding back energy to the power grid. The output has the characteristics of simulating the characteristics of various batteries, setting different serial and parallel connection node numbers and charging and discharging of the batteries under different battery electric quantities. The output of the battery emulator 101 has a programmable function and can be used in a variety of situations by different control software. The battery output characteristic and the battery charging and discharging can be simulated. The power supply can enable a user to select the type, the serial section number, the parallel section number and the battery electric quantity index of the simulation battery, thereby comprehensively simulating the output characteristic of the battery, including the process of battery internal resistance characteristic change in the battery discharging process. In addition, the battery simulation apparatus 101 uses a multithreading technique, a database technique, a fast data storage module design, a customizable report, and a multi-format report output. Specifically, the input end of the battery simulator 101 is connected to the dc terminal of the converter under test 102 through the first switch S1.
In this embodiment, the converter to be detected 102 includes one of an energy storage converter, a photovoltaic grid-connected inverter, and a light storage complementary ac, the type and capacity of the converter can be changed according to the actual detection requirement, the detection of the megawatt converter can be realized to the maximum extent, and the detection requirement of the product diversity of the converter can be met. Specifically, the dc end of the converter to be tested 102 is connected to the battery simulator 101 through the first switch S1, the ac end of the converter to be tested 102 is connected to the second switch S2, and the converter to be tested 102 can convert ac power to dc power.
In this embodiment, the second switch S2 is a selection switch, and may be connected to the power grid simulation apparatus 104 or the power grid fault simulation generation apparatus 105, respectively, and may be connected to different apparatuses according to different detection requirements of the detection platform, so as to implement different detections.
Specifically, the grid simulator 104 provides various disturbances to the testing platform, including voltage fluctuation, voltage sag/drop, harmonic disturbance, three-phase imbalance, etc., and simulates various conditions that may occur in the grid. Each phase voltage value can be independently regulated and programmed, the frequency value can be regulated and programmed, and electric energy can flow in two directions.
In this embodiment, two ends of the power grid simulation device 104 form a loop through the third switch S3, where the third switch S3 controls the operation of the power grid simulation device 104, when the third switch S3 is closed, the power grid simulation device 104 is short-circuited and is in a state of stopping working, and when the third switch S3 is open, the power grid simulation device 104 is in a state of working, so that the third switch S3 controls the operation of the power grid simulation device 104, and the converter to be tested can be directly connected to the power grid for related detection.
Specifically, the grid fault simulation device 105 includes a low voltage fault occurrence device and a high voltage fault occurrence device. The low-voltage ride through detection environment and the high-voltage ride through environment are simulated respectively, and high-voltage and low-voltage ride through combined test can be realized. The low-voltage fault generation device uses the passive reactor to simulate the voltage drop of a power grid, and can simulate three-phase symmetrical voltage drop, phase-to-phase voltage drop and single-phase voltage drop. The high-voltage fault generating device adopts a passive device and consists of a current-limiting reactor, a boosting capacitor, a damping resistor and a circuit breaker. Three-phase symmetrical voltage rise can be simulated.
In this embodiment, the input terminal of the grid simulator 104 is connected to the power supply device 106 through the first isolation transformer 108, and the input terminal of the grid fault simulator is connected to the power supply device 106 through the first isolation transformer 108. That is to say, the first isolation transformer 108 and the second isolation transformer 109 are connected to the power supply device 106 together, wherein the voltage of the power supply device 106 is 10kV, the voltages at both ends of the second isolation transformer 109 are the same and are both 10kV, the voltage at the side of the first isolation transformer 108 connected to the power supply device is 10kV, and the voltage at the end connected to the grid simulation device 104 is 380V.
Specifically, two ends of the measuring device 103 are connected to the dc end and the ac end of the converter 102, respectively, and collect ac/dc performance parameter data of the converter 102. The measuring device 103 comprises a voltage transformer, a current transformer, a power analyzer, an electric energy quality analyzer, an oscilloscope and the like, collects performance parameter data of a direct current end and an alternating current end of the converter 102 for test project data, and finally performs systematic data analysis and unified processing, and simultaneously provides a test report according to a preset format.
Specifically, the anti-islanding RLC device 107 accesses the detection platform through the fourth switch S4, wherein an access point of the anti-islanding RLC device 107 is located between the second switch S2 and the grid simulation device 104. The anti-islanding RLC device 107 is composed of a resistive load, an inductive load and a capacitive load, and is provided with an electrical parameter detection system. The three-phase load power is independently controlled, the power input is controlled in a sectional type combination mode, various power loads can be simulated in any combination mode, the full-automatic loading measurement capability is achieved, and the detection requirement of an anti-islanding effect test is met.
In this embodiment, by controlling the starting of different switches and devices, the performance parameters of the converter 102 collected by the measuring device 103 may change, and a user may adjust the battery simulator 101, the converter 102 and other devices according to different detection requirements, thereby realizing the detection of different items by the detection platform, such as anti-islanding detection, charge-discharge detection, voltage adaptability detection and the like. Meanwhile, a battery simulator is selected to replace a traditional bidirectional direct-current power supply and a traditional direct-current load, a converter detection platform is simplified, the type and the capacity of the converter 102 can be changed according to actual detection requirements, the detection capacity can reach megawatt level, and the detection requirement of the product diversity of the converter is met. The details of the current transformer detection platform of the present embodiment are specifically described below, and the following description is only provided for the sake of understanding, and is not necessary to implement the present embodiment.
A second embodiment of the invention relates to a current transformer testing platform. The second embodiment is substantially the same as the first embodiment, and mainly differs therefrom in that: in the second embodiment, the converter detection platform further includes a first multi-tap transformer 210, a second multi-tap transformer 211, and a centralized control center 212.
As shown in fig. 2, the current transformer detection platform in this embodiment specifically includes: the system comprises a battery simulation device 201, a converter 202, a measuring device 203, a grid simulation device 204, a grid fault simulation generation device 205, a power supply device 206, an anti-islanding RLC device 207, a first switch S1, a second switch S2, a third switch S3, a fourth switch S4, a first multi-tap transformer 210, a second multi-tap transformer 211, a first isolation transformer 208, a second isolation transformer 209 and a centralized control center 212.
Since the first embodiment corresponds to the present embodiment, the present embodiment can be implemented in cooperation with the first embodiment. The related technical details mentioned in the first embodiment are still valid in this embodiment, and the technical effects that can be achieved in the first embodiment can also be achieved in this embodiment, and are not described herein again in order to reduce the repetition.
In the present embodiment, the first multi-tap transformer 210 and the second multi-tap transformer 211 are included, the first multi-tap transformer 210 is located between the second switch S2 and the grid simulation device, and the second multi-tap transformer 211 is located between the second switch S2 and the grid fault simulation generation device. The secondary sides of the first multi-tap transformer 210 and the second multi-tap transformer 211 have multiple voltage levels, so that the detection platform can be matched with the detection of converters with different voltage levels, and megawatt detection can be realized to the maximum extent.
In this embodiment, the system further comprises a centralized control center, the centralized control center is connected with the first switch S1, the second switch S2, the third switch S3, the fourth switch S4, the battery simulation device 201, the converter to be tested 202, the measurement device 203, the grid simulation device 204, the grid fault simulation generation device 205, and the anti-islanding RLC device 207, and the centralized control center 212 realizes remote control of the detection platform.
Specifically, the centralized control center 212 can connect the battery simulation device 201, the grid simulation device 204, the grid fault simulation generation device 205, and the anti-islanding RLC device 207 to the same system through the remote control switches S1-S4, perform the unified on-off operation of the switches of the test system, control the on-off operation of different switches according to different detection items, and enable a user to quickly perform the switching operation between different detection items.
The centralized control center 212 performs remote control operation on the battery simulation device 201 and the converter 202 to be tested through remote control software, the test process can be automatically tested according to a pre-programmed program, meanwhile, a data acquisition system integrated by a detection platform perhaps generates corresponding test data, and simultaneously, a test report is automatically generated according to a format defined by a user.
In this embodiment, the centralized control center 212 pre-stores a software system, is in a modular format, has high expandability, and can expand and add measurement and control functions of different test items according to factory inspection needs. The detection platform provides an intelligent detection operation platform which is used for controlling and displaying all circuit breakers and contactors in the switch and can control the starting stop, emergency stop and control parameter setting of a direct-current power supply, an alternating-current power supply, island equipment and a direct-current load in a test system.
In this embodiment, the sequence of the automatic detection process of the detection platform sequentially includes: software initialization, user request input of test items, equipment sending work sequence designation, equipment output test according to designated sequence, data storage, data analysis and processing, and test report generation.
Specifically, a user requests to input a test item for selecting the test item by the user, wherein the test item comprises anti-islanding detection, charge and discharge detection, voltage adaptability detection, low voltage ride through detection, high voltage ride through detection and the like; the appointed equipment sends a work sequence which is used for sending the work sequence to the detection platform as the software system has the equipment participating in the test and the sequence participating in the test in the current detection after determining a specific detection project; then, the equipment outputs a test according to a specified sequence to realize the detection; the data analysis processing is used for carrying out relevant calculation analysis according to the data uploaded by the data acquisition device, displaying and storing the original data into a database in the forms of charts and the like; and finally, generating a test report, automatically generating a word document form report according to the corresponding data analysis result and the obtained chart, and judging whether the corresponding test is qualified or not according to the corresponding evaluation standard.
The detection platform of the embodiment can also realize the omnibearing real state simulation of the operating state of the Battery Management System (BMS). The method provides accurate scientific basis for the evaluation of the safety and reliability of the BMS system, and can be applied to the fields of BMS type tests, factory tests, performance detection, research and development of the BMS management system and the like.
This embodiment is through centralized control center, and the connection between the different equipment of control is closed and the disconnection to the switch of control difference for the user can swiftly carry out the switching between the different detection projects according to the demand, thereby reaches the higher effect of degree of automation.
A third embodiment of the present invention relates to a detection method for a converter detection platform, and as shown in fig. 3, the detection method of the present embodiment specifically realizes anti-islanding detection, and includes the following steps:
step 301, setting the working mode of the converter to be a grid-connected mode and island protection time.
And step 302, setting a second switch to be connected with the power grid simulation device, and closing the first switch and the third switch.
Specifically, after the converter and the battery simulator are put into use, whether the running state of the current detection platform is correct or not is judged, if the running state of the current detection platform is normal, the step 303 is performed, if the running state of the current detection platform is abnormal, the second switch and the third switch are disconnected, the state of the current detection platform is checked and repaired, and the step 301 is performed again after the repair.
Step 303, adjusting the battery simulation device to make the output power of the converter be the rated ac output power.
And 304, setting the fourth switch to be in a closed state, so that the anti-islanding RLC device is in a working state.
305, adjusting quality factor Q of anti-islanding RLC devicef。
Specifically, the quality factor Qf＝1.0，QfThe error of (2) is not more than 0.05.
Step 306, adjusting the current of the alternating current end of the converter;
specifically, the current at the alternating current end of the regulating converter is less than 1% of the output current in a steady state.
Step 307, the second switch is opened, and the island operation time t is measured and recorded1。
In particular, the island run time t1To turn off the second switch until the output current drops to 1% of the rated current.
And 308, connecting the second switch to the power grid simulation device again, and adjusting the converter to be in a grid-connected mode.
Step 309, adjusting the anti-islanding RLC device to enable the active power and the reactive power output by the converter to meet the requirement of standard deviation, wherein the standard deviation is ± 5.
Step 310, the second switch is disconnected, and the island operation time t is measured and recorded2。
Step 311, t2Whether or not it is greater than t1If t is2Greater than t1Go to step 312; if t2Less than t1Then return to step 309.
Specifically, if t2Less than t1Then, returning to step 309, the active power and the reactive power output by the converter are continuously adjusted by a deviation of 1% according to the standard requirement.
Step 312, outputting a test report.
A fourth embodiment of the present invention relates to a detection method for a current transformer detection platform, and as shown in fig. 4, the detection method of the present embodiment specifically implements charge and discharge detection, and as shown in fig. 4, includes the following steps:
step 401, setting the operation power of the power grid simulation device to be the rated charging power PCSetting charging time of converter to TCWherein the rated charging power PCThe rated power of the AC end of the converter.
Step 402, setting the output power of the battery simulator to the rated discharge power PfSetting the discharge time of the converter to Tf。
And step 403, setting the operation mode of the converter to be a charging mode.
And step 404, setting a second switch to be connected with the power grid simulation device, closing the first switch and opening the third switch.
Specifically, after the power grid simulation device, the battery simulation device and the converter are put into use, whether the current operation state of the detection platform is normal or not is judged, if the current operation state of the detection platform is normal, the step 405 is performed, and if the current operation state of the network is abnormal, the second switch is turned off, and the step 401 is performed again.
Step 405, when the charging time reaches TCAt this time, the operation mode of the inverter is set to the discharging mode, and in this embodiment,charging time TCIs 3 min.
Specifically, after the operation mode of the converter is set to be the discharging mode, whether the operation state of the detection platform is normal or not is judged, if the operation state of the detection platform is normal, step 406 is performed, and if the operation state of the detection platform is abnormal, the second switch is turned off, and step 401 is performed again.
Step 406, measuring and recording the waveform change of the DC end of the converter, and calculating the time interval t from 90% of rated charging power to 90% of rated discharging powera。
Step 407, when the charging time reaches TfIn the present embodiment, the operation mode of the converter is set as the charging mode, and the charging time T is set as the charging time TfIs 3 min.
Specifically, after the operation mode of the converter is set to be the charging mode, whether the state of the current detection platform is normal is determined, if the state of the current detection platform is normal, step 408 is performed, and if the state of the current detection platform is abnormal, the second switch is turned off, and step 407 is performed again.
Step 408, measuring and recording the waveform change of the direct current end of the converter, and calculating the time interval t from 90% of rated discharge power to 90% of rated charge powerb。
In step 409, charge/discharge switching time t ═ is calculated (t)a+tb)/2。
Step 410, outputting a test report.
The fifth embodiment of the present invention relates to a detection method for a current transformer detection platform, which specifically implements voltage adaptability detection, and as shown in fig. 5, includes the following steps:
step 501, setting the working mode of the converter to be a grid-connected working mode.
Step 502, a second switch is set to be connected with the power grid simulation device, the first switch is closed, and the third switch is opened.
Specifically, after the converter, the battery simulator and the grid simulator are put into use, whether the current detection platform is normal or not is judged, if the current detection platform is normal, the step 503 is performed, if the current detection platform is abnormal, the second switch is turned off, the current detection platform is checked and repaired, and after the current detection platform is repaired, the step 501 is performed again.
Step 503, adjusting the output voltage of the power grid simulation device to be three values of 86% -109% Un.
Specifically, Un is the rated voltage of the access system, and the output voltage of the grid simulator is set to 86% Un, the intermediate value and 109% Un.
And step 504, measuring and recording the frequency, the state and the action condition of the output end of the converter.
Specifically, after step 503, the detection platform operates for 4s, and then starts to measure and record the frequency, state, and operation condition of the output end of the converter, and if the converter operates, the converter needs to be reset, and then step 505 is performed.
And 505, adjusting the output voltage of the power grid simulation device to be three values of 111% -119% Un.
Specifically, the output voltage of the grid simulator is set to 111% Un, the intermediate value, 119% Un.
And step 506, measuring and recording the frequency, the state and the action condition of the output end of the converter.
Specifically, after step 505, after the detection platform is operated for 4s, the frequency, state and operation of the output end of the converter are measured and recorded, and if the converter is operated, the converter needs to be reset, and then step 507 is performed.
And step 507, adjusting the output voltage of the power grid simulation device to 121% Un.
And step 508, measuring and recording the frequency, the state and the action condition of the output end of the converter.
Specifically, after the detection platform runs for 4s after step 507, the frequency, the state and the action condition of the output end of the converter are measured and recorded.
And 509, disconnecting the second switch and setting the working mode of the converter to be a grid-connected discharging mode.
Step 510, close the second switch.
Step 511, judging whether the current detection platform state is normal, if the detection platform state is normal, entering step 512, if the detection platform state is abnormal, disconnecting the second switch, checking the detection platform state and repairing, and after repairing, entering step 509 again.
And step 512, outputting a test report.
It will be understood by those of ordinary skill in the art that the foregoing embodiments are specific embodiments for practicing the invention, and that various changes in form and details may be made therein without departing from the spirit and scope of the invention in practice.