Test apparatus and method for metering performance of electricity meters

Abstract

This application discloses a testing device and method for the metering performance of an electricity meter. The device includes: a standard electricity meter; a programmable switch unit; a test signal output unit, including voltage terminals and current terminals, with the voltage terminals connected in parallel to both the standard electricity meter and the electricity meter under test, and the positive terminal of the current terminal connected sequentially to the standard electricity meter, the programmable switch unit, the electricity meter under test, and the negative terminal; an error calculation unit connected to both the standard electricity meter and the electricity meter under test; and a control unit connected to the test signal output unit, the standard electricity meter, the programmable switch unit, the electricity meter under test, and the error calculation unit. The device of this application can perform metering performance tests for frequent forward and reverse switching of electricity meters and for inconsistent three-phase current directions; the method, used with the described device, solves the problem that existing electricity meter testing methods are functionally limited and do not meet the actual operating conditions of electricity meters in new energy scenarios.

Description

Technical Field

[0001] This application relates to the field of electric energy metering, and particularly to an electric energy meter metering performance test device and method. Background Art

[0002] In recent years, China has vigorously implemented the renewable energy substitution action, and the development of photovoltaic power generation and wind power generation has been rapid. The country has also put forward the strategic goal of building a new power system with new energy as the main body. New energy power generation is significantly affected by environmental and climatic characteristics, showing characteristics such as randomness, volatility, and intermittency. Taking rooftop photovoltaic power generation of residents as an example, when the sunlight is sufficient on sunny days, the photovoltaic power generation power is large, and while meeting the self-use electricity of residents, it can also send electricity to the public grid; at night and on rainy and cloudy days, the photovoltaic power generation power is low, and users need to obtain electricity from the public grid. Due to the access of new energy power generation, the operating conditions of electric energy meters have changed, requiring them to accurately measure forward and reverse electric energy.

[0003] In the current technical specifications of smart electric energy meters, it is clearly required to carry out error tests on the power flow in both forward and reverse directions. Specifically, the forward metering performance test of an electric energy meter refers to that both the standard electric energy meter and the tested electric energy meter work in the forward metering environment, that is, the current flowing through the standard electric energy meter and the current flowing through the tested electric energy meter are both forward; after the test, if the increment of the total active electric energy measured by the tested electric energy meter in the forward direction is consistent with the increment of the total active electric energy measured by the standard electric energy meter in the forward direction, it indicates that the tested electric energy meter passes the test. The reverse metering performance test of an electric energy meter refers to that the standard electric energy meter works in the forward metering environment, and the tested electric energy meter works in the reverse metering environment, that is, the current flowing through the standard electric energy meter is forward and the current flowing through the tested electric energy meter is reverse; after the test, if the increment of the total active electric energy measured by the tested electric energy meter in the reverse direction is consistent with the increment of the total active electric energy measured by the standard electric energy meter in the forward direction, it indicates that the tested electric energy meter passes the test. However, the existing test methods simply adopt all forward or negative power flow tests, without considering the frequent change of the power flow in both forward and reverse directions, nor the situation where the three-phase current directions are inconsistent. Therefore, the existing test methods do not conform to the actual operating conditions of electric energy meters in the new energy scenario. When the power flow direction changes frequently on site, or when the direction of one of the three-phase currents is inconsistent with the directions of the other two-phase currents, the accuracy of electric energy metering cannot be guaranteed. Summary of the Invention

[0004] In view of this, this application provides an electric energy meter metering performance test device and method, which solves the problems that the existing electric energy meter test device and method have a single function and do not conform to the actual operating conditions of electric energy meters in the new energy scenario while ensuring accuracy.

[0005] According to one aspect of this application, an electric energy meter metering performance test device is provided, including:

[0006] Standard electricity meter;

[0007] Programmable switch unit;

[0008] The test signal output unit includes multiple voltage terminals and multiple current terminals. Each voltage terminal is connected in parallel to the standard energy meter and the energy meter under test, respectively. The positive terminal of the current terminal, the standard energy meter, the programmable switch unit, the energy meter under test, and the negative terminal of the current terminal are connected in sequence.

[0009] An error calculation unit is connected to both the standard energy meter and the energy meter under test.

[0010] The control unit is connected to the test signal output unit, the standard energy meter, the programmable switch unit, the energy meter under test, and the error calculation unit, respectively.

[0011] Optionally, the programmable switch unit is configured to change the switch state according to the control command of the control unit to change the direction of the current flowing into the tested energy meter;

[0012] Accordingly, the error calculation unit is configured to calculate the error of the tested energy meter based on the current direction.

[0013] According to another aspect of this application, a method for testing the metering performance of an electricity meter is provided, the method comprising:

[0014] The control unit initializes and configures the standard energy meter, the programmable switch unit, the test signal output unit, and the error calculation unit.

[0015] The test signal output unit outputs voltage and current signals;

[0016] The control unit controls the programmable switch unit to change the switch state, thereby changing the direction of the current signal flowing into the tested energy meter;

[0017] The error calculation unit calculates the error of the tested energy meter based on the active energy increment of the tested energy meter and the standard energy meter under different current directions.

[0018] Optionally, controlling the programmable switch unit to change the switch state to alter the direction of the current flowing into the tested energy meter includes:

[0019] Within a preset total test duration, the switch state is changed once every preset period to alter the direction of the current.

[0020] Optionally, changing the switch state once every preset period within a preset total test duration includes:

[0021] After the current signal is output, timing begins. When the timing duration reaches T0, the current output of the test signal output unit is turned off, and the programmable switch unit is controlled to change the switch state so that the current signal is reversed and timing restarts.

[0022] After the timing duration reaches T1, the current output is activated;

[0023] Restart timing and return to the step of turning off the current output of the test signal output unit after the timing duration reaches T0, until the total duration reaches the total duration threshold corresponding to the preset total test duration range.

[0024] Optionally, the step of calculating the error of the tested energy meter based on the active energy increment of the tested energy meter and the standard energy meter under different current directions includes:

[0025] according to Calculate the first error E1 of the tested electricity meter.

[0026] Among them, Q 正 Q represents the positive active energy increment of the tested energy meter within the preset total test duration. 反 Q is the increase in reverse active energy of the tested energy meter within the preset total test duration. 标 The positive active energy increment of the standard energy meter within the preset total test duration.

[0027] Optionally, after calculating the first error E1 of the tested energy meter, the method further includes:

[0028] If the first error is not greater than the first preset error threshold, then the tested energy meter is determined to have passed the metering performance test of frequent forward and reverse switching.

[0029] Optionally, the test signal output unit outputs a voltage signal and a current signal, including:

[0030] The test signal output unit outputs a voltage signal;

[0031] The test signal output unit outputs a first current signal that meets the first preset condition and a second current signal that meets the second preset condition, wherein the first preset condition is Ia+Ib≠Ic and the second preset condition is Ia+Ib=Ic.

[0032] Accordingly, the control of the programmable switch unit to change the switch state, thereby altering the direction of the current flowing into the tested energy meter, includes:

[0033] Under the first preset condition, the programmable switch unit is controlled to change the switch state so that the tested energy meter operates in the (Ia,Ib,-Ic) state as the first state;

[0034] Under the first preset condition, the programmable switch unit is controlled to change the switch state so that the tested energy meter operates in the (-Ia,-Ib,Ic) state as the second state;

[0035] Under the second preset condition, the programmable switch unit is controlled to change the switch state so that the tested energy meter operates in the (Ia,Ib,-Ic) state, which is the third state.

[0036] Optionally, the step of calculating the error of the tested energy meter based on the active energy increment of the tested energy meter and the standard energy meter under different current directions includes:

[0037] The positive active energy increment Q of phase A of the tested energy meter is read. A正 The reverse active energy increment Q of the tested energy meter (A) A反 The positive active energy increment Q of phase B of the tested energy meter B正 The B-direction active energy increment Q of the tested energy meter B反 The positive active energy increment Q of phase C of the tested energy meter C正 and the C-direction active energy increment Q of the tested energy meter. C反 ;

[0038] according to Calculate the second error E2 of the tested energy meter.

[0039] Optionally, after calculating the second error E2 of the tested energy meter, the method further includes:

[0040] If the second error is not greater than the second preset error threshold, then the tested energy meter is determined to have passed the three-phase current direction inconsistency metering performance test.

[0041] By employing the above technical solution, this application provides a testing device and method for the metering performance of an electricity meter. Firstly, based on conducting forward and reverse metering performance tests on the electricity meter under test, this device can also perform metering performance tests involving frequent changes in forward and reverse directions, as well as tests for inconsistent three-phase current directions. This aligns with the actual operating conditions of electricity meters and fills the gaps in existing testing methods. Secondly, during forward and reverse metering performance tests, the standard electricity meter always operates in a forward metering environment, ensuring the accuracy of the reference energy value provided by the standard meter. Furthermore, this invention uses a programmable switch unit to automatically change the circuit state, which can flexibly change the current direction of the electricity meter under test, significantly improving the efficiency of forward and reverse metering performance testing.

[0042] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0043] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0044] Figure 1 This paper shows a schematic diagram of the structure of an energy meter metering performance testing device provided in an embodiment of this application;

[0045] Figure 2 This paper shows a schematic diagram of the structure of a programmable switch unit of an energy meter metering performance testing device provided in an embodiment of this application;

[0046] Figure 3 A flowchart illustrating another method for testing the metering performance of an electricity meter provided in an embodiment of this application is shown.

[0047] Figure 4 A flowchart illustrating another method for testing the metering performance of an electricity meter provided in an embodiment of this application is shown.

[0048] Figure 5 A flowchart illustrating another method for testing the metering performance of an electricity meter provided in an embodiment of this application is shown.

[0049] In the picture:

[0050] 1 Control unit, 2 Test signal output unit, 3 Programmable switch unit, 4 Standard energy meter, 5 Error calculation unit, 6 Energy meter under test. Detailed Implementation

[0051] The present application will be described in detail below with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in the embodiments of the present application can be combined with each other.

[0052] This embodiment provides a device for testing the metering performance of an electricity meter, such as... Figure 1 As shown, the device includes a control unit 1, a test signal output unit 2, a programmable switch unit 3, a standard energy meter 4, and an error calculation unit 5.

[0053] Among them, Figure 1 As shown, the control unit 1 serves as the control center of the entire device and is connected to the test signal output unit 2, the programmable switch unit 3, the standard energy meter 4, and the error calculation unit 5 via communication lines, enabling bidirectional communication.

[0054] The control unit 1 controls the test signal output unit 2 via communication line 1 to generate voltage and current test signals, ensuring that the output test signals meet the test requirements; it controls the programmable switch unit 3 via communication line 2 to change the loop state, altering the direction of current flow into the tested energy meter 6; it configures the range of the standard energy meter 4 via communication line 3 to match the specifications of the tested energy meter 6; communication line 4 controls the error calculation unit 5 to perform error calculation; communication line 5 acquires the energy data of the standard energy meter 4; and communication line 6 acquires the energy data of the tested energy meter 6.

[0055] Test signal output unit 2 can output three-phase voltage test signals, with four voltage terminals: Ua, Ub, Uc, and Un. These voltage signals are connected in parallel to the standard energy meter 4 and the energy meter under test 6, respectively. It can also output three-phase current test signals: phase A current (corresponding to positive terminal Ia+ and negative terminal Ia-), phase B current (corresponding to positive terminal Ib+ and negative terminal Ib-), and phase C current (corresponding to positive terminal Ic+ and negative terminal Ic-). The positive terminal corresponding to each phase current, the standard energy meter 4, the programmable switch unit 3, the energy meter under test 6, and the corresponding negative terminal are connected sequentially. The programmable switch unit 3 is also connected to the energy meter under test 6, ensuring that the three-phase current first flows into the standard energy meter 4, then through the programmable switch unit 3 into the energy meter under test 6, and finally back to the test signal output unit 2.

[0056] The programmable switch unit 3 is used to change the switch state according to the instructions issued by the control unit 1, thereby changing the direction of the current loop. All three phase current loops can be controlled independently. Taking the A-phase current loop as an example, the current flowing into the Ia+ terminal of the programmable switch unit 3 can be controlled to flow out from the I1+ or I1- terminal to the tested energy meter 6. When it is required that the A-phase current flows forward through the tested energy meter 6, the programmable switch unit 3 can be configured to make the A-phase current flow out from the I1+ terminal, flow back from the I1- terminal, and finally return to the test signal output unit 2 from the Ia- terminal of the programmable switch unit. When it is required that the A-phase current flows backward through the tested energy meter 6, the programmable switch unit 3 can be configured to make the A-phase current flow out from the I1- terminal, flow back from the I1+ terminal, and finally return to the test signal output unit 2 from the Ia- terminal of the programmable switch unit 3. The control methods for the B-phase and C-phase current loops are similar. In practical applications, the current flowing through the standard ammeter is always positive, while the direction of the current flowing through the tested energy meter 6 is controlled by the programmable switch unit 3.

[0057] The standard energy meter 4 is used to measure the accumulated energy value of the voltage test signal and the current test signal on the standard energy meter 4, and the energy measured by the standard energy meter 4 is used as a reference value. The standard energy meter 4 and the energy meter under test 6 are connected in parallel in voltage and in series in current. The current flowing through the standard energy meter 4 is always positive, and the direction of the current flowing through the energy meter under test 6 is controlled by the programmable switch unit 3.

[0058] Error calculation unit 5 is used to calculate the measurement error of the tested energy meter 6. Error calculation unit 5 is connected to control unit 1 via communication line 4, connected to standard energy meter 4 via communication line 5, and connected to the tested energy meter 6 via communication line 6. According to the instructions of control unit 1, error calculation unit 5 obtains the energy data of standard energy meter 4 and tested energy meter 6, and calculates the error of tested energy meter 6 with the energy value of standard energy meter 4 as a reference value.

[0059] This device can be used for traditional forward and reverse metering performance tests of electricity meters. In addition, it can be used for metering performance tests under conditions of frequent changes in current direction and inconsistent three-phase current directions. During the forward metering performance test, all three-phase currents flowing through the tested electricity meter 6 are in the forward direction; during the reverse metering performance test, all three-phase currents flowing through the tested electricity meter 6 are in the reverse direction; during both forward and reverse metering performance tests, the current direction flowing through the tested electricity meter 6 frequently changes, sometimes all in the forward direction and sometimes all in the reverse direction, repeating this cycle multiple times.

[0060] in, Figure 2The diagram shows the structure of the programmable switch unit 3. Its function is to change the internal switch connection state according to the instructions of the control unit 1, thereby changing the direction of the current flowing into the tested energy meter 6. Specifically, this function can be achieved by simulating a switch or relay to change the switch state. Taking the A-phase current loop as an example, controlling the switch state of the programmable switch unit 3 to connect Ia+ with I1+ and I1- with Ia- allows the A-phase current to flow forward through the tested energy meter 6; changing the switch state of the programmable switch unit 3 to connect Ia+ with I1- and I1+ with Ia- allows the A-phase current to flow backward through the tested energy meter 6. During the test, the control unit 1 sends instructions to control the state of the programmable switch unit 3, which can flexibly change the current direction according to the test requirements, significantly improving the efficiency of testing the forward and reverse metering performance of the energy meter.

[0061] Based on this structure, the programmable switch changes its state according to the control command of the control unit 1 to change the direction of the current flowing into the tested energy meter 6. Thus, the tested energy meter 6 can obtain the active energy increment under different current direction conditions, and the error calculation unit 5 can calculate the error of the tested energy meter 6 based on the active energy increment under different current direction conditions.

[0062] Furthermore, embodiments of this application provide a method for testing the metering performance of an electricity meter, wherein the method is executed by a control unit controlling other units, such as... Figure 3 As shown, the method includes:

[0063] Step 301: The control unit initializes and configures the standard energy meter, the programmable switch unit, the test signal output unit 2, and the error calculation unit.

[0064] Step 302: The test signal output unit outputs voltage and current signals;

[0065] Step 303: The programmable switch unit changes the switch state to change the direction of the current signal flowing into the tested energy meter.

[0066] Step 304: The error calculation unit calculates the error of the tested energy meter based on the active energy increment of the tested energy meter and the standard energy meter under different current directions.

[0067] In this embodiment, the control unit 1 first initializes and configures each functional module, configuring the parameter information of the standard energy meter 4 and adjusting the range of the standard energy meter 4 to match that of the energy meter under test 6. The control unit adjusts the switching state of the programmable switch unit to its initial state and initializes the states of other units. Then, the test signal output unit 2 outputs the voltage and current signals required for the test, and the programmable switch unit 3 changes its switching state, thus changing the direction of the current flowing into the energy meter under test 6. The error calculation unit 5 reads the active energy increment of the energy meter under test 6 under different current directions, as well as the active energy increment of the standard energy meter 4, and calculates the error of the energy meter under test 6 based on the read results.

[0068] Optionally, this method can be used for tests where the current direction changes frequently. Specifically, in step 303, the programmable switch unit changes its switch state to change the direction of the current signal flowing into the tested energy meter, including:

[0069] Within the preset total test duration, the switching state is changed once every preset cycle to change the current direction.

[0070] Specifically, timing begins after the current signal is output. When the timing duration reaches T0, the current output of the test signal output unit 2 is turned off, and the programmable switch unit 3 is controlled to change its switch state so that the current signal is reversed and timing restarts. When the timing duration reaches T1, the current output is turned on. Timing restarts and returns to the step of turning off the current output of the test signal output unit 2 after the timing duration reaches T0, until the total timing duration reaches the total timing threshold corresponding to the preset total testing duration range.

[0071] In this embodiment, the switching state of the programmable switch is changed at regular intervals to reverse the current flowing into the tested energy meter 6, thereby achieving frequent changes in the current direction and enabling the test under conditions of frequent changes in the current direction.

[0072] Specifically, Figure 4 The figure illustrates a schematic diagram of the specific operation flow of the experiment involving frequent changes in current direction according to an embodiment of this application. As shown in the figure, the method includes the following steps:

[0073] Step 401: The control unit initializes and configures each functional module;

[0074] Step 402: The test signal output unit generates the voltage and current signals required for the test;

[0075] Step 403: After time T0, turn off the current output of the test signal output unit;

[0076] Step 404: The programmable switch unit changes the circuit structure to reverse the direction of the three-phase current;

[0077] Step 405: After time T1, turn on the current output of the test signal output unit;

[0078] Step 406: Has the total test time T been reached? If not, return to step 403; if yes, proceed to step 407.

[0079] Step 407: Stop the test and calculate the error of the tested energy meter.

[0080] In this embodiment, during the test of frequently changing current direction on the tested energy meter 6, the current direction of the standard energy meter 4 remains positive, ensuring the accuracy of the energy reference value provided by the standard energy meter 4. The current direction of the tested energy meter 6 changes between forward and reverse directions with a period of T0+T1, and the total test time is T. The programmable switch unit 3 automatically changes the circuit state, which can flexibly change the current direction of the tested energy meter 6, improving the testing efficiency. During the test, to improve accuracy, the period of current forward and reverse changes is on the order of minutes, and the number of changes is greater than 100 times.

[0081] The error of the test with frequent changes in current direction, i.e., the first error E1 of the tested energy meter 6, can be calculated using the following formula:

[0082]

[0083] Among them, Q 正 Q represents the positive active energy increment of the tested energy meter 6 within the preset total test duration. 反 Q represents the increase in reverse active energy of the tested energy meter 6 within the preset total test duration. 标 The positive active energy increment of the standard energy meter 4 within the preset total test duration is considered. If the first error is not greater than the first preset error threshold, the tested energy meter 6 is determined to have passed the metering performance test of frequent forward and reverse switching.

[0084] Optionally, this method can also be used for tests under conditions of inconsistent three-phase currents. Specifically, in step 303, the test signal output unit outputs voltage and current signals, including:

[0085] Test signal output unit 2 outputs voltage signal; test signal output unit 2 outputs a first current signal that meets the first preset condition and a second current signal that meets the second preset condition, wherein the first preset condition is Ia+Ib≠Ic and the second preset condition is Ia+Ib=Ic;

[0086] Accordingly, the programmable switch unit 3 changes its switch state to alter the direction of the current signal flowing into the tested energy meter 6, including:

[0087] Under the first preset condition, the programmable switch unit 3 is controlled to change its switch state to the first state so that the tested energy meter 6 operates in the (Ia,Ib,-Ic) state; under the first preset condition, the programmable switch unit 3 is controlled to change its switch state so that the tested energy meter 6 operates in the (-Ia,-Ib,Ic) state as the second state; under the second preset condition, the programmable switch unit 3 is controlled to change its switch state to the third state so that the tested energy meter 6 operates in the (Ia,Ib,-Ic) state.

[0088] In this embodiment, under the first preset condition, i.e., when Ia+Ib≠Ic, the test is performed on the tested energy meter 6 in two different states: (Ia,Ib,-Ic) and (-Ia,-Ib,Ic). These two states correspond to the cases where the forward current is greater than the reverse current and the case where the forward current is less than the reverse current, respectively. This allows the metering performance of the tested energy meter 6 in both forward and reverse scenarios with total active power. Under the second preset condition, i.e., when Ia+Ib=Ic, the test is performed on the tested energy meter 6 in the state of (Ia,Ib,-Ic). This state corresponds to the case where the forward current is equal to the reverse current. This allows the metering performance of the tested energy meter 6 in the scenario where the total active power is 0.

[0089] Specifically, Figure 5 The figure shows a schematic diagram of the specific operation process for a test under the condition of inconsistent three-phase current directions according to an embodiment of this application. As shown in the figure, the method includes the following steps:

[0090] Step 501: The control unit initializes and configures each functional module;

[0091] Step 502: The test signal output unit generates the voltage signal required for the test;

[0092] Step 503: The test signal output unit generates a current signal that meets the condition Ia+Ib≠Ic;

[0093] Step 504: The programmable switch unit changes the circuit structure and changes the current flow direction, so that the tested energy meter 6 operates under two conditions: (Ia, Ib, -Ic) and (-Ia, -Ib, Ic).

[0094] Step 505: Obtain the error of the tested energy meter under different conditions through the error calculation unit;

[0095] Step 506: The test signal output unit generates a current signal that meets the condition Ia + Ib = Ic;

[0096] Step 507: The programmable switch unit changes the circuit structure and changes the current flow direction, so that the meter under test operates under the conditions of (Ia, Ib, -Ic);

[0097] Step 508: Obtain the error of the tested energy meter through the error calculation unit.

[0098] The error of the three-phase current direction inconsistency test, which is also the second error E2 of the tested energy meter 6, can be calculated using the following formula:

[0099] The positive active energy increment Q of phase A of the tested energy meter 6 is read from the tested energy meter 6. A正 The positive active energy increment Q of the tested energy meter 6 in the opposite direction (A) A反 The positive active energy increment Q of phase B of the tested energy meter 6 B正 The B-direction active energy increment Q of the tested energy meter 6 B反 The positive active energy increment Q of phase C of the tested energy meter 6 C正 and the reverse active energy increment Q of the tested energy meter 6. C反 ;

[0100]

[0101] Among them, Q A正 The positive active energy increment of phase A of the tested energy meter 6, Q A反 The A-direction active energy increment and Q of the tested energy meter 6 are... B正 The positive active energy increment of phase B of the tested energy meter 6, Q B反 The B-direction active energy increment and Q of the tested energy meter 6 are... C正 The positive active energy increment of phase C of the tested energy meter 6, Q C反 The second error is the increase in active energy in the opposite direction of the C phase of the tested energy meter 6. If the second error is not greater than the second preset error threshold, the tested energy meter 6 is determined to have passed the metering performance test with different three-phase current directions.

[0102] It is understandable that, since the total active power of the energy meter is the algebraic sum of the active power of phases A, B, and C, during the test of inconsistent three-phase current directions, the sum of the total positive and negative active energy increments of the tested energy meter 6 will be lower than the positive active energy increment Q of the standard energy meter 4 during the test period. 标 .

[0103] In specific application scenarios, the ammeter under test can be subjected to forward metering performance tests, reverse metering performance tests, frequent forward and reverse switching metering performance tests, and three-phase current direction metering performance tests. If each test is passed, the tested energy meter 6 is deemed to have passed the metering performance test.

[0104] It should be noted that other corresponding descriptions of the functional modules involved in the electricity meter metering performance testing device provided in this application embodiment can be found in the corresponding descriptions in the above method, and will not be repeated here.

[0105] Through the above description of the embodiments, those skilled in the art can clearly understand that this application can be implemented by means of software plus necessary general-purpose hardware platform, or it can be implemented by hardware.

[0106] Those skilled in the art will understand that the accompanying drawings are merely schematic diagrams of a preferred embodiment, and the units or processes shown in the drawings are not necessarily essential for implementing this application. Those skilled in the art will understand that the units in the apparatus of the embodiment can be distributed within the apparatus of the embodiment as described, or can be located in one or more apparatuses different from this embodiment, with corresponding changes. The units of the above-described embodiment can be combined into one unit, or further divided into multiple sub-units.

[0107] The serial numbers in this application are for descriptive purposes only and do not represent the superiority or inferiority of any particular implementation scenario. The above disclosures are merely a few specific implementation scenarios of this application; however, this application is not limited thereto, and any variations conceived by those skilled in the art should fall within the protection scope of this application.

Claims

1. A testing device for the metering performance of an electricity meter, characterized in that, The device includes: Standard electricity meter; The programmable switch unit is used to change the switch state and change the direction of the current loop according to the instructions issued by the control unit, and to independently control the three-phase current loop. The control includes: under a first preset condition, changing the switch state to a first state so that the tested energy meter operates in the (Ia, Ib, -Ic) state; under the first preset condition, changing the switch state to a second state so that the tested energy meter operates in the (-Ia, -Ib, Ic) state; under a second preset condition, changing the switch state to a third state so that the tested energy meter operates in the (Ia, Ib, -Ic) state. The first preset condition is Ia + Ib ≠ Ic, and the second preset condition is Ia + Ib = Ic. The current flowing through the standard energy meter is always positive, and the direction of the current flowing through the tested energy meter is controlled by the programmable switch unit. The test signal output unit includes multiple voltage terminals and multiple current terminals. Each voltage terminal is connected in parallel to the standard energy meter and the energy meter under test, respectively. The positive terminal of the current terminal, the standard energy meter, the programmable switch unit, the energy meter under test, and the negative terminal of the current terminal are connected in sequence. The error calculation unit is connected to both the standard energy meter and the energy meter under test, and reads the positive active energy increment Q of phase A of the energy meter under test. A正 The reverse active energy increment Q of the tested energy meter (A) A反 The positive active energy increment Q of phase B of the tested energy meter B正 The B-direction active energy increment Q of the tested energy meter B反 The positive active energy increment Q of phase C of the tested energy meter C正 and the C-direction active energy increment Q of the tested energy meter. C反 ,according to Calculate the second error E2 of the tested energy meter, where Q 标 This refers to the positive active energy increment of the standard energy meter within the preset total test duration. The control unit is connected to the test signal output unit, the standard energy meter, the programmable switch unit, the energy meter under test, and the error calculation unit, respectively.

2. The apparatus according to claim 1, characterized in that, The programmable switch unit is configured to change the switch state according to the control command of the control unit, so as to change the direction of the current flowing into the tested energy meter; Accordingly, the error calculation unit is configured to calculate the error of the tested energy meter based on the current direction.

3. A method for testing the forward and reverse metering performance of an electricity meter, characterized in that, The method is applied to the apparatus as described in claim 2, the method comprising: The control unit initializes and configures the standard energy meter, the programmable switch unit, the test signal output unit, and the error calculation unit. The test signal output unit outputs voltage and current signals; The programmable switch unit changes the switch state to change the direction of the current signal flowing into the tested energy meter; The error calculation unit calculates the error of the tested energy meter based on the active energy increment of the tested energy meter and the standard energy meter under different current directions.

4. The method according to claim 3, characterized in that, The programmable switch unit changes the switch state to alter the direction of the current flowing into the tested energy meter, including: Within a preset total test duration, the switch state is changed once every preset period to alter the direction of the current.

5. The method according to claim 4, characterized in that, The step of changing the switch state once every preset period within a preset total test duration includes: After the current signal is output, timing begins. When the timing duration reaches T0, the current output of the test signal output unit is turned off, and the programmable switch unit is controlled to change the switch state so that the current signal is reversed and timing restarts. After the timing duration reaches T1, the current output is activated; Restart timing and return to the step of turning off the current output of the test signal output unit after the timing duration reaches T0, until the total duration reaches the total duration threshold corresponding to the preset total test duration range.

6. The method according to claim 5, characterized in that, The calculation of the error of the tested energy meter based on the active energy increment of the tested energy meter and the standard energy meter under different current directions includes: according to Calculate the first error E1 of the tested electricity meter. Among them, Q 正 Q represents the positive active energy increment of the tested energy meter within the preset total test duration. 反 Q is the increase in reverse active energy of the tested energy meter within the preset total test duration. 标 The positive active energy increment of the standard energy meter within the preset total test duration.

7. The method according to claim 6, characterized in that, After calculating the first error E1 of the tested energy meter, the method further includes: If the first error is not greater than the first preset error threshold, then the tested energy meter is determined to have passed the metering performance test of frequent forward and reverse switching.

8. The method according to claim 3, characterized in that, The test signal output unit outputs voltage and current signals, including: The test signal output unit outputs a voltage signal; The test signal output unit outputs a first current signal that meets the first preset condition and a second current signal that meets the second preset condition, wherein the first preset condition is Ia+Ib≠Ic and the second preset condition is Ia+Ib=Ic. Accordingly, the programmable switch unit changes the switch state to change the direction of the current signal flowing into the tested energy meter, including: Under the first preset condition, the programmable switch unit is controlled to change the switch state to the first state so that the tested energy meter works in the (Ia,Ib,-Ic) state; Under the first preset condition, the programmable switch unit is controlled to change the switch state to the second state so that the tested energy meter works in the (-Ia,-Ib,Ic) state; Under the second preset condition, the programmable switch unit is controlled to change the switch state to the third state so that the tested energy meter operates in the (Ia,Ib,-Ic) state.

9. The method according to claim 3, characterized in that, After calculating the second error E2 of the tested energy meter, the method further includes: If the second error is not greater than the second preset error threshold, then the tested energy meter is determined to have passed the three-phase current direction inconsistency metering performance test.

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