A performance test system and method for a low-voltage treatment device of an energy storage type terminal power grid

Abstract

The application provides a kind of energy storage type terminal power grid low voltage management device performance test system and method, wherein the test system includes isolation voltage regulator, adjustable resistor, adjustable reactor, electric quantity recording instrument, switch.The application can flexibly adjust the test system parameters according to the actual use scene and control logic of the device after connecting the energy storage type low voltage management device into the test system, simulate the voltage change condition, and thus efficiently and conveniently verify and evaluate the low voltage management function of the device.The application can truly simulate the operation environment of remote weakly connected power grid, use common electrical equipment and elements such as isolation voltage regulator, adjustable resistor and sliding reactor to build the test system, effectively simulate different voltage conditions of terminal power grid under light load, normal load and heavy load conditions, and thus test the functional characteristics of energy storage type low voltage management device, greatly improving the test efficiency.

Description

Technical Field

[0001] This invention relates to the field of energy storage technology applications, specifically a performance testing system and method for an energy storage-type end-grid low-voltage management device. Background Technology

[0002] Remote, weakly connected power grids are far from the core distribution network area and generally suffer from large distribution radius, long transmission lines, outdated equipment, low power reliability, and poor power quality. This results in high line loss and significant voltage drops during power transmission. Furthermore, the seasonal and unbalanced loads prevalent in rural power grids exacerbate the conflict between residential and industrial electricity needs, leading to severe low voltage conditions at the grid's end. Existing reactive power compensation and on-load tap regulation methods are ineffective in addressing these issues, and conventional grid upgrade schemes using 10kV grid structures also present significant financial burdens.

[0003] The energy storage-type low-voltage management device is based on a rectifier-inverter module, an energy storage battery module, a dedicated control system module, and a communication module. It is connected in parallel to the line towers or cable branch boxes at the end-user residential areas. Through optimal energy control strategies, it stores energy to supplement power during periods of light load and higher voltage, such as late at night. During peak electricity consumption periods, it automatically compensates the grid with power, raising the system voltage. It can effectively solve the power quality problems such as occasional low voltage and frequent large-scale voltage fluctuations caused by insufficient active power transmission capacity in the current end-user grid, providing a low-cost and high-efficiency solution for low voltage problems in rural power grids. Summary of the Invention

[0004] The purpose of this invention is to provide a functional testing system and testing method for an energy storage-type low-voltage management device for end-grid networks. After connecting the energy storage-type low-voltage management device to the testing system, the voltage environment under different conditions of remote weakly connected power grids can be realistically simulated. The parameters of the testing system can be flexibly adjusted according to the actual use scenario and control logic of the device to simulate voltage changes, thereby efficiently and conveniently verifying and evaluating the low-voltage management function of the device and accurately verifying the function of the low-voltage management device.

[0005] This invention provides a performance testing system for an energy storage-type end-grid low-voltage management device, comprising an isolation voltage regulator, an adjustable resistor, an adjustable reactor, a power recorder, and a switch. The isolation voltage regulator is used to simulate the transformer substation in a rural power grid, providing power to the testing system. The adjustable resistor is used to simulate the line resistance from the substation to the end user and the user's active load; by adjusting its size, it can effectively simulate different conditions of heavy load, normal load, and light load on the line. The adjustable reactor is used to simulate the reactive load in a rural power grid; by adjusting its size, it can simulate common power factor changes in rural power grids. The power recorder is used to record the voltage, current, and power of various components in the testing system. The switch is used to control the on / off state of various components in the testing system.

[0006] Furthermore, the adjustable resistor includes a first adjustable resistor, a second adjustable resistor, and a third adjustable resistor. The switches include switches K1, K2, and K3. One end of the isolation voltage regulator is connected to one end of the first adjustable resistor via switch K1. The other end of the first adjustable resistor is connected to one end of the second adjustable resistor via switch K2. The other end of the first adjustable resistor is also connected to one end of the third adjustable resistor via switch K3. The other end of the third adjustable resistor is connected to one end of the adjustable reactor. The other end of the adjustable reactor is connected to the other end of the second adjustable resistor, and then connected to the other end of the isolation voltage regulator. The treatment device is connected to the rear side of the first adjustable resistor in parallel. The power waveform recorder is connected to the front side of the first adjustable resistor, the inlet of the treatment device, and the rear side of the second adjustable resistor via clamp-on CT. The two ends of the isolation voltage regulator and the two ends of the treatment device are connected via a dedicated PT measurement wiring.

[0007] A functional testing method for an energy storage-type low-voltage control device, using the testing system described in claim 2, comprises the following steps:

[0008] Step a: After the test system is set up, all switches (K1, K2, K3) are in the off state. Set the impedance values ​​of the first adjustable resistor Z1, the second adjustable resistor Z2, the third adjustable resistor Z3, and the adjustable reactor Z. After setting, close the main power switch on the front side of the isolation voltage regulator and adjust the output of the isolation voltage regulator to 242V and keep it unchanged.

[0009] Step b, test the automatic power replenishment function of the device under high voltage: close switch K1 to put the low voltage treatment device into operation. At this time, the voltage at the low voltage treatment access point is in a high range. Monitor the low voltage treatment action characteristics, power P, Q and I, U changes at various points, and observe whether the low voltage treatment carries out energy storage power replenishment according to the control logic to reduce the access point voltage to the normal operating range.

[0010] Step c, test the standby function of the device under normal voltage: close switch K2 to put the low voltage treatment device into operation. At this time, the voltage at the connection point of the low voltage treatment device is within the normal range. Monitor the operating characteristics, power P, Q and I, U changes of the low voltage treatment device, and observe whether the low voltage treatment device maintains the standby state according to the control logic and does not exchange active and reactive power with the line. After the test is completed, open switch K2.

[0011] Step d: Test the compensation and control function of the device under low voltage: Close switch K3 to put the low voltage control device into operation. At this time, the voltage at the connection point of the low voltage control device is in a low range. Monitor the operating characteristics, power P, Q and I, U changes of the low voltage control device. Observe whether the low voltage control device performs reactive power compensation operation according to the control logic based on the system power factor. When the reactive power compensation cannot achieve the expected effect, perform active power compensation by discharging energy storage. Finally, raise the connection point voltage to the normal operating range. After the test is completed, open switch K3.

[0012] Step e: Disconnect switch K1, adjust the output of the isolation voltage regulator to 0, disconnect the main power switch on the front side of the isolation voltage regulator, and the test ends.

[0013] Furthermore, the impedance value Z1 of the first adjustable resistor is equivalent to the equivalent impedance value of the distribution line and the front-end user from the transformer outlet to the terminal grid, and is set to 2 to 5 Ω; the impedance value Z2 of the second adjustable resistor is equivalent to the impedance value of the terminal user when the terminal voltage level is normal, and is set to 10 to 25 Ω; the impedance value Z3 of the third adjustable resistor is equivalent to the impedance value of the terminal user when the terminal voltage level is low, and is set to 4 to 10 Ω; the impedance value Z of the adjustable reactor is equivalent to the impedance value of the terminal user when the terminal voltage level is low.

[0014] Furthermore, the normal operating range of the access point voltage is 200V≤U≤220V.

[0015] Furthermore, in step b, the voltage at the connection point is in a relatively high range of 220V < U ≤ 264V.

[0016] Furthermore, in step d, the voltage at the access point is in a low range, U < 200V.

[0017] The present invention has the following beneficial effects:

[0018] 1. The testing system of this invention can realistically simulate the operating environment of remote weakly connected power grids. By simulating the characteristics of remote weakly connected power grids, a testing system is built. Using common electrical equipment and components such as isolation voltage regulators, adjustable resistors, and sliding reactors, it effectively simulates different voltage conditions of the end power grid under light load, normal load, and heavy load conditions, creating favorable conditions for preparing to evaluate the operating characteristics of energy storage-type low-voltage control devices. 2. The testing method is efficient and convenient. After the parameters of the isolation voltage regulator, adjustable resistor, and sliding reactor are set, no adjustments are required during the test. The voltage level at the device connection point can be adjusted simply by opening and closing the switch, thereby testing the functional characteristics of the device under different voltage levels, greatly improving the testing efficiency. Attached Figure Description

[0019] Figure 1This is an equivalent test principle diagram of the functional test system for the energy storage-type end-grid low voltage management device of the present invention;

[0020] Figure 2 This is a schematic diagram of the functional testing system for the energy storage-type end-grid low-voltage management device of the present invention;

[0021] Figure 3 This is a flowchart of the performance testing method for the energy storage-type end-grid low-voltage management device of the present invention. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] like Figure 1 As shown, based on the structural characteristics of remote and weakly interconnected distribution areas, looking forward from the end low-voltage node O, the front-end distribution network structure can be simplified to an active linear two-port network composed of distribution area transformers, line losses, and user loads along the line. Using Thevenin's theorem, this can be equivalent to a structure of voltage sources in series with adjustable impedance. Looking backward from the end low-voltage node O, after connecting the governance device, the back-end user-side structure can be equivalent to a structure of current sources in parallel with adjustable impedance using Norton's theorem. After this equivalent transformation, the schematic diagram of the remote and weakly interconnected power grid test system can be obtained.

[0024] like Figure 2 As shown in the diagram, based on the equivalent transformation of the remote weak grid test system, this embodiment of the invention utilizes an isolation voltage regulator, an adjustable resistor, an adjustable reactor, a power recorder, a switch, and wires to construct a performance test system for an energy storage-type end-grid low-voltage governance device, simulating the actual use environment of the governance device in a remote weak grid.

[0025] Among them, the isolation voltage regulator simulates the transformer in the rural power grid and provides power to the test system;

[0026] The adjustable resistor is used to simulate the line resistance from the transformer substation to the end user and the active load of the user. By adjusting its size, it can effectively simulate different conditions of heavy load, normal and light load of the line. In this embodiment of the invention, the adjustable resistor has three parts, namely a first adjustable resistor, a second adjustable resistor and a third adjustable resistor.

[0027] Adjustable reactors are used to simulate reactive loads in rural power grids. By adjusting their size, they can simulate common power factor changes in rural power grids.

[0028] The power waveform recorder is used to record electrical quantities such as voltage, current, and power in various parts of the test system; switches (K1, K2, K3) are used to control the on / off state of various parts of the test system.

[0029] The wires provide an electrical path for the test system.

[0030] One end of the isolation voltage regulator is connected to one end of the first adjustable resistor via switch K1. The other end of the first adjustable resistor is connected to one end of the second adjustable resistor via switch K2. The other end of the first adjustable resistor is also connected to one end of the third adjustable resistor via switch K3. The other end of the third adjustable resistor is connected to one end of the adjustable reactor. The other end of the adjustable reactor is connected to the other end of the second adjustable resistor, and then connected to the other end of the isolation voltage regulator. The treatment device is connected to the rear side of the first adjustable resistor in parallel. The power waveform recorder is connected to the front side of the first adjustable resistor, the inlet of the treatment device, and the rear side of the second adjustable resistor via clamp-on CT. The two ends of the isolation voltage regulator and the two ends of the treatment device are connected via a dedicated PT measurement wiring.

[0031] like Figure 3 As shown, this embodiment of the invention also provides a functional testing method for an energy storage-type low-voltage control device. The overall testing logic is as follows:

[0032] (1) Test the automatic power replenishment function of the device under high voltage. When the voltage at the access point is higher than the normal operating range (220V<U≤264V), prioritize energy storage charging to ensure the energy storage battery is in good condition, and at the same time reduce the voltage at the access point to the normal operating range.

[0033] (2) Test the standby function of the device under normal voltage. When the voltage U at the device connection point is normal (200V≤U≤220V), the device is in standby mode and does not exchange power with the external system.

[0034] (3) Test the compensation and management function of the device under low voltage. When the voltage at the device connection point is lower than the normal operating range (U<200V), prioritize the release of reactive power compensation operation based on the system power factor. When the reactive power compensation cannot achieve the expected effect, perform energy storage discharge active power compensation to raise the voltage at the connection point to the normal operating range.

[0035] The method is implemented according to the following steps:

[0036] Step a: With all switches K1, K2, and K3 in the open state, set the impedance values ​​of the adjustable resistors Z1 (equivalent to the equivalent impedance of the distribution line from the transformer outlet to the terminal grid and the front-end user, with a reference value of 2-5Ω), Z2 (equivalent to the impedance of the terminal user when the terminal voltage level is normal, with a reference value of 10-25Ω), and Z3 (equivalent to the impedance of the terminal user when the terminal voltage level is low, with a reference value of 4-10Ω). Set the impedance value of the adjustable reactor Z (equivalent to the impedance of the terminal user when the terminal voltage level is low, adjusted according to the set power factor range). After setting, close the main power switch on the front side of the isolation voltage regulator, adjust the output of the isolation voltage regulator to 242V and keep it unchanged.

[0037] Step b: Test the automatic power replenishment function of the high-voltage treatment device. Close switch K1 to put the low-voltage treatment device into operation. At this time, the voltage at the connection point of the treatment device is in a high range (220V < U ≤ 264V). Monitor the operating characteristics, power P, Q, and I, U changes of the treatment device at various points using a power waveform recorder. Observe whether the treatment device performs energy storage replenishment according to the control logic to reduce the connection point voltage to the normal operating range (200V ≤ U ≤ 220V).

[0038] Step c: Test the standby function of the low-voltage control device under normal voltage. Close switch K2 to put the low-voltage control device into operation. At this time, the voltage at the device connection point is within the normal range (200V≤U≤220V). Monitor the operating characteristics of the control device, power P, Q, and changes in I and U at various points. Observe whether the control device maintains the standby state according to the control logic and does not exchange active or reactive power with the line using a power waveform recorder (the power waveform recorder displays P=0, Q=0, I=0). After the test is completed, open switch K2.

[0039] Step d: Test the compensation and control function of the device under low voltage. Close switch K3 to put the low voltage control device into operation. At this time, the voltage at the device's connection point is in a low range (U < 200V). Monitor the device's operating characteristics, power P, Q, and changes in I and U at various points. Use a power waveform recorder to observe whether the device prioritizes reactive power compensation based on the system power factor according to the control logic. When reactive power compensation fails to achieve the expected effect, it performs active power compensation by discharging stored energy, ultimately raising the connection point voltage to the normal operating range (200V ≤ U ≤ 220V). After the test is completed, disconnect switch K3.

[0040] Step e: Disconnect switch K1, adjust the output of the isolation voltage regulator to 0, disconnect the main power switch on the front side of the isolation voltage regulator, and the test ends.

[0041] The beneficial effects of this invention are:

[0042] (1) The test system realistically simulates the operating environment of remote weak grids. By simulating the characteristics of remote weak grids, a test system is built. Using common electrical equipment and components such as isolation voltage regulators, adjustable resistors, and sliding reactors, the system effectively simulates the different voltage conditions of the end grid under light load, normal load, and heavy load conditions, creating favorable conditions for preparing to evaluate the operating characteristics of energy storage-type low voltage control devices.

[0043] (2) The testing method is efficient and convenient. After the parameters of the isolation voltage regulator, adjustable resistor and sliding reactor are set, no adjustment is required during the test. The voltage level of the device connection point can be adjusted by simply opening and closing the switch, so as to test the functional characteristics of the device under different voltage levels, which greatly improves the testing efficiency.

[0044] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A performance testing system for an energy storage-type end-grid low-voltage management device, characterized in that: The system includes an isolation voltage regulator, an adjustable resistor, an adjustable reactor, a power recorder, and a switch. The isolation voltage regulator simulates the transformer substation in a rural power grid, providing power to the test system. The adjustable resistor simulates the line resistance from the substation to the end user and the user's active load; by adjusting its size, it can effectively simulate different conditions of heavy load, normal load, and light load. The adjustable reactor simulates the reactive load in a rural power grid; by adjusting its size, it can simulate common power factor changes in rural power grids. The power recorder records the voltage, current, and power of various components in the test system. The switch controls the on / off state of various components in the test system. The adjustable resistor includes a first adjustable resistor, a second adjustable resistor, and a third adjustable resistor. The switches include switches K1, K2, and K3. One end of the isolation voltage regulator is connected to one end of the first adjustable resistor via switch K1. The other end of the first adjustable resistor is connected to one end of the second adjustable resistor via switch K2. The other end of the first adjustable resistor is also connected to one end of the third adjustable resistor via switch K3. The other end of the third adjustable resistor is connected to one end of the adjustable reactor. The other end of the adjustable reactor is connected to the other end of the second adjustable resistor, and then connected to the other end of the isolation voltage regulator. The treatment device is connected to the rear side of the first adjustable resistor in parallel. The power waveform recorder is connected to the front side of the first adjustable resistor, the inlet of the treatment device, and the rear side of the second adjustable resistor via clamp-on CT. The two ends of the isolation voltage regulator and the two ends of the treatment device are connected via a dedicated PT measurement wiring.

2. A performance testing method for an energy storage-type end-grid low-voltage management device, characterized in that, The test is performed using the testing system described in claim 1, and the method includes the following steps: Step a: After the test system is set up, all switches (K1, K2, K3) are in the off state. Set the impedance values ​​of the first adjustable resistor Z1, the second adjustable resistor Z2, the third adjustable resistor Z3, and the adjustable reactor Z. After setting, close the main power switch on the front side of the isolation voltage regulator and adjust the output of the isolation voltage regulator to 242V and keep it unchanged. Step b, test the automatic power replenishment function of the device under high voltage: close switch K1 to put the low voltage treatment device into operation. At this time, the voltage at the low voltage treatment access point is in a high range. Monitor the low voltage treatment action characteristics, power P, Q and I, U changes at various points, and observe whether the low voltage treatment carries out energy storage power replenishment according to the control logic to reduce the access point voltage to the normal operating range. Step c, test the standby function of the device under normal voltage: close switch K2 to put the low voltage treatment device into operation. At this time, the voltage at the connection point of the low voltage treatment device is within the normal range. Monitor the operating characteristics, power P, Q and I, U changes of the low voltage treatment device, and observe whether the low voltage treatment device maintains the standby state according to the control logic and does not exchange active and reactive power with the line. After the test is completed, open switch K2. Step d: Test the compensation and control function of the device under low voltage: Close switch K3 to put the low voltage control device into operation. At this time, the voltage at the connection point of the low voltage control device is in a low range. Monitor the operating characteristics, power P, Q and I, U changes of the low voltage control device. Observe whether the low voltage control device performs reactive power compensation operation according to the control logic based on the system power factor. When the reactive power compensation cannot achieve the expected effect, perform active power compensation by discharging energy storage. Finally, raise the connection point voltage to the normal operating range. After the test is completed, open switch K3. Step e: Disconnect switch K1, adjust the output of the isolation voltage regulator to 0, disconnect the main power switch on the front side of the isolation voltage regulator, and the test ends.

3. The performance testing method for the energy storage-type end-grid low-voltage management device as described in claim 2, characterized in that: The impedance value Z1 of the first adjustable resistor is equivalent to the equivalent impedance value of the distribution line and the front-end user from the transformer outlet to the terminal grid, and is set to 2~5Ω; the impedance value Z2 of the second adjustable resistor is equivalent to the impedance value of the terminal user when the terminal voltage level is normal, and is set to 10~25Ω; the impedance value Z3 of the third adjustable resistor is equivalent to the impedance value of the terminal user when the terminal voltage level is low, and is set to 4~10Ω; the impedance value Z of the adjustable reactor is equivalent to the impedance value of the terminal user when the terminal voltage level is low.

4. The performance testing method for the energy storage-type end-grid low-voltage management device as described in claim 2, characterized in that: The normal operating range of the access point voltage is 200V≤U≤220V.

5. The performance testing method for the energy storage-type end-grid low-voltage management device as described in claim 2, characterized in that: In step b, the voltage at the connection point is in a relatively high range: 220V < U ≤ 264V.

6. The performance testing method for the energy storage-type end-grid low-voltage management device as described in claim 2, characterized in that: In step d, the voltage at the connection point is in a low range, U < 200V.

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