Electric energy meter and power supply device and control method for electric energy meter and power collection terminal detection platform

Abstract

This invention discloses a power supply device and control method for a testing platform for electricity meters and electricity consumption data acquisition terminals, relating to the field of electricity meter and electricity consumption data acquisition terminal testing. The power supply device includes a power source, an isolation transformer, a control unit, and relays corresponding to each meter position. The isolation transformer is connected to the power grid and to the normally closed contacts of the relays. The power source is connected to the normally open contacts of the relays, and the common terminal of the relays is connected to the meters. The control method includes: upon power-on, all normally closed contacts of the relays close, and the isolation transformer supplies power to all meters to start them; after the meters and power source stabilize, the control unit executes an equal-phase-zero-voltage time-sharing control strategy, controlling the relays to operate in a time-sharing manner, causing each meter to sequentially switch to power supply from the power source. This invention, through the coordinated operation of the isolation transformer and power source and precise zero-crossing switching, achieves smooth startup of multiple meter positions while avoiding surge impacts on the power source, effectively improving the load-bearing capacity and testing efficiency of the testing platform, and reducing equipment costs.

Description

Technical Field

[0001] This invention relates to the field of testing electricity meters and electricity consumption data acquisition terminals, and specifically to a power supply device and control method for a testing platform for electricity meters and electricity consumption data acquisition terminals. Background Technology

[0002] The testing platform for electricity meters and electricity consumption data acquisition terminals is an important device for verifying the metering accuracy of electricity meters. It typically includes a power source, a standard electricity meter, and an error detection unit. During testing, the power source provides voltage and current signals that meet the test requirements to both the meter under test and the standard electricity meter. The standard electricity meter serves as the measurement benchmark, generating a standard electricity value. The error detection unit collects the electricity pulses from the meter under test and calculates its measured value, thus obtaining the error deviation relative to the standard electricity value, thereby completing the accuracy assessment. With the advancement of electricity consumption data acquisition systems, current testing platforms often need to simultaneously connect a large number of electricity meters for parallel testing. Large platforms simultaneously supporting 48 or even 96 electricity meters have become common configurations.

[0003] However, a prominent technical problem exists in actual testing: when a large number of electricity meters are powered on simultaneously, the capacitor charging during startup generates a significant surge current due to their internal switching power supplies. This peak current often far exceeds the steady-state current during normal operation. If the testing platform supplies power to all connected meters at the same time, the cumulative effect of these surge currents will severely impact the power source. This can lead to slow voltage build-up, delayed control loop response, and extended test preparation time; in severe cases, it may damage critical components within the power source, affecting the safe and stable operation of the equipment. Especially with the increasing number of functional modules in electricity meters and the differences in power supply solutions from different manufacturers, the overall power consumption of the meters is increasing, further intensifying the requirements for the power source's load-carrying capacity.

[0004] To address the aforementioned issues, existing testing systems typically employ two approaches: First, reducing the number of meters tested per cycle to lower instantaneous power requirements. However, this directly leads to decreased testing efficiency, failing to meet the demands of large-scale verification. Second, using a higher-power power source to increase capacity and cope with surge impacts. However, as high-precision instruments, power sources are designed with the accuracy and stability of their output waveforms in mind, rather than short-term overload capacity. Simply increasing the rated power not only significantly increases equipment costs but also results in substantial power redundancy during normal testing, leading to waste. Therefore, achieving a smooth start-up when multiple meters are powered on, while balancing testing efficiency, equipment cost, and safety and stability, has become a pressing issue in current testing system design. Summary of the Invention

[0005] This invention proposes a power supply device and control method for an energy meter and power consumption acquisition terminal testing platform. Its purpose is to achieve a smooth start-up of the testing platform when multiple meters are powered on simultaneously, while taking into account testing efficiency, equipment cost and operational safety and stability.

[0006] The technical solution of this invention is as follows:

[0007] A power supply device for a testing platform for electricity meters and electricity consumption data acquisition terminals includes a power source, an error detection unit, and multiple meter installation stations, as well as a standard meter installed at one of the meter installation stations. The voltage output terminal of the power source is used to electrically connect to each meter installation station to supply power to each meter. The error detection unit is used to communicate with the meter under test and the standard meter. The power supply device for the testing platform for electricity meters and electricity consumption data acquisition terminals also includes an isolation transformer, a control unit, and relays corresponding to each meter installation station.

[0008] The voltage input terminal of the isolation transformer is connected to the power grid, and the voltage output terminal is connected to the normally closed contacts of each relay; the voltage output terminal of the power source is connected to the normally open contacts of each relay; the common terminal of the relay is electrically connected to the meter at the corresponding meter installation station.

[0009] The control unit is electrically connected to each relay and controls each relay to perform switching actions based on the equal phase-zero voltage time-division switching control strategy.

[0010] As a further improvement to the power supply device of the energy meter and the power consumption acquisition terminal detection platform, it also includes a first voltage transformer. The input end of the first voltage transformer is connected to the voltage output end of the isolation transformer, and the output end is connected to the control unit. It is used to collect the output voltage waveform of the isolation transformer in real time and feed it back to the control unit.

[0011] As a further improvement to the power supply device of the power meter and power consumption acquisition terminal detection platform, it also includes a second voltage transformer. The input end of the second voltage transformer is connected to the voltage output end of the power source, and the output end is connected to the control unit. It is used to collect the output voltage waveform of the power source in real time and feed it back to the control unit.

[0012] As a further improvement to the power supply device of the energy meter and the power consumption acquisition terminal detection platform: the control unit is also communicatively connected to the power source and is used to adjust the phase of the power source output voltage according to the phase of the isolation transformer.

[0013] As a further improvement to the power supply device of the energy meter and power consumption acquisition terminal detection platform: the control unit also includes a drive voltage adjustment module corresponding to each relay, which is used to provide drive voltage to the corresponding relay.

[0014] A power supply control method for an energy meter and electricity consumption data acquisition terminal testing platform, the power supply control method being based on the aforementioned power supply device for the energy meter and electricity consumption data acquisition terminal testing platform, includes the following steps:

[0015] Step S1, Power-on start-up stage: The control unit controls all relays to be in a de-energized state, keeping the common terminal of each relay closed with the normally closed contact, and the meters at each meter installation station draw power from the power grid through the isolation transformer and start up.

[0016] Step S2, Power Supply Switching Stage: After all meters and power sources have started up, the control unit begins to execute the equal phase-zero voltage time-sharing switching control strategy, controlling each relay to be energized and activated in a time-sharing manner, so that the power supply source of the corresponding meter is switched from the isolation transformer to the power source;

[0017] Step S3, Detection Stage: After all relays have switched, the power source provides the voltage and current signals required for detection to all meters, and the error detection unit performs error detection on the tested energy meter.

[0018] As a further improvement to the power supply control method for the energy meter and power consumption acquisition terminal detection platform, it also includes step S0, which is executed before step S1 begins:

[0019] Step S0, Relay Self-Test Synchronization Stage: The control unit adjusts the drive voltage of each relay so that the time it takes for all relays to separate from the normally closed contact at the common terminal and to contact the normally open contact at the common terminal is consistent when they operate.

[0020] As a further improvement to the power supply control method for the energy meter and power consumption acquisition terminal detection platform, step S0 specifically includes:

[0021] Step S0-1: The control unit sequentially applies multiple different driving voltages to each relay, measures and records the time interval Δt between the time t2 when the common terminal separates from the normally closed contact and the time t3 when the common terminal contacts the normally open contact under each driving voltage, and establishes a driving voltage-time interval mapping relationship for each relay.

[0022] Step S0-2: The control unit determines a common time interval ΔT that can be achieved by all relays based on the mapping relationship of all relays;

[0023] Step S0-3: The control unit searches for the corresponding driving voltage for each relay in reverse according to the common time interval ΔT, and uses the driving voltage as the working voltage for the subsequent operation of the relay, so that the switching time of all relays in the subsequent switching process is ΔT.

[0024] As a further improvement to the power supply control method for the energy meter and power consumption acquisition terminal detection platform, step S0 further includes:

[0025] Step S0-4: Adjust the phase of the power source according to the common time interval ΔT, so that the time value corresponding to the phase difference between the power source and the isolation transformer is equal to the common time interval ΔT.

[0026] As a further improvement to the power supply control method for the aforementioned energy meter and power consumption acquisition terminal detection platform:

[0027] In step S0, for each relay: the moment when the control unit starts applying the working voltage corresponding to the common time interval ΔT is recorded as t1, and the time interval ΔT_delay from t1 to t2 is recorded;

[0028] The equal-phase-zero-voltage time-sharing control strategy described in step S2 refers to: calculating the time of each zero-crossing point in the future time based on the waveform of the output voltage of the isolation transformer; assigning the start time of action to all relays in a preset order, with the start time of action of each relay corresponding to a different zero-crossing point of the output voltage of the isolation transformer;

[0029] During switching, let the start time of a certain relay's action be t_action, and take the time interval ΔT_delay recorded by the relay in step S0. Take the time t_action-ΔT_delay as the time when the control unit starts to apply the working voltage, so that the time t2 when the relay separates from the normally closed contact from the common terminal is exactly the start time t_action, and the time t3 when the common terminal contacts the normally open contact is exactly the next zero-crossing time of the power source.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] 1. This invention significantly improves the load-carrying capacity of the testing platform when multiple meters are simultaneously powered on, by introducing an isolation transformer and a power source working in tandem and employing a control strategy based on equal-phase-zero-voltage time-sharing switching, while maintaining the original capacity of the power source. Since all meters draw power from the grid through the isolation transformer during startup, the direct impact of surge current on the power source is avoided. Therefore, there is no need to select an ultra-large capacity power source to cope with instantaneous high currents, nor is there a limitation on the number of meters, greatly reducing equipment costs, ensuring testing efficiency, and eliminating waste caused by power redundancy during normal testing.

[0032] 2. This invention uses a control unit to perform time-sharing switching of each relay, allowing the meter to smoothly transition from the isolation transformer to the power source sequentially after startup. During this process, the relay switching time is precisely controlled near the voltage zero-crossing point, and the switching time is extremely short, much shorter than the holding time of the meter's internal energy storage capacitor. This effectively avoids the generation of secondary surge currents and improves the reliability and safety of the system operation.

[0033] 3. This invention further incorporates a relay self-test and synchronous calibration mechanism. By adjusting the drive voltage of each relay to ensure consistent switching times, and combining this with a phase adjustment strategy, it ensures that the moments when the normally closed contact disconnects the isolation transformer and the normally open contact connects to the power source are precisely controlled near the zero-crossing point of their respective voltage waveforms. This design not only eliminates switching deviations caused by differences in component parameters but also minimizes contact arcing, extending the electrical life of the relays. Furthermore, since both the disconnection of the isolation transformer and the connection of the power source occur at zero-crossing points, the continuity and purity of the voltage waveform during switching are guaranteed, providing a stable power supply foundation for subsequent high-precision testing.

[0034] In summary, this invention solves the bottleneck problem of power source startup difficulties in multi-position detection with extremely low hardware cost, which not only improves the compatibility and detection efficiency of the detection platform, but also provides a practical and feasible technical path for the standardization and mass application of detection equipment. Attached Figure Description

[0035] Figure 1 A schematic diagram of the power supply device for the testing platform of the electricity meter and electricity consumption data acquisition terminal;

[0036] Figure 2 This diagram illustrates the relationship between the relay switching time and the output waveforms of the isolation transformer and the power source. Detailed Implementation

[0037] The technical solution of the present invention will now be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0038] like Figure 1 As shown in the figure, the power supply device for the testing platform of the electricity meter and power consumption acquisition terminal described in this embodiment is applied to a scenario of parallel testing of multiple electricity meters. The testing platform includes a power source, an error detection unit, and multiple meter installation stations, with a standard meter serving as the measurement reference installed at one of the meter installation stations. The meter can be an electricity meter or a power consumption acquisition terminal; in this embodiment, it is a single-phase electricity meter. The voltage output terminal of the power source is used to electrically connect to each meter installation station, thereby providing the voltage signal required for testing to the meter under test and the standard meter installed thereon. The error detection unit is communicatively connected to the meter under test and the standard meter, used to collect the power pulses of both and calculate the error value.

[0039] To enhance the load-bearing capacity of the testing platform during startup and prevent surge current from impacting the power source, this embodiment introduces an isolation transformer, a control unit, and relays corresponding to each meter installation station, building upon the aforementioned structure. The voltage input terminal of the isolation transformer is connected to the power grid, and its voltage output terminal is connected to the normally closed contact (NC) of each relay. The voltage output terminal of the power source is connected to the normally open contact (NO) of each relay. The common terminal (CM) of the relays is electrically connected to the power input terminal of the corresponding meter at the installation station (e.g., the L terminal of a single-phase energy meter). In this embodiment, the N terminal of the single-phase energy meter is directly connected to the common output terminal, which is connected to the neutral wire.

[0040] Furthermore, the control unit is electrically connected to each relay to control the timing of each relay's operation according to a set strategy. Through this connection method, each meter at each installation station can switch between two power sources: an isolation transformer and a power source, with the switching process coordinated uniformly by the control unit.

[0041] The control unit is further connected to a first voltage transformer and a second voltage transformer. The input terminal of the first voltage transformer is connected to the voltage output terminal of the isolation transformer and the aforementioned common output terminal, and its output terminal is connected to the control unit. This allows for real-time acquisition of the output voltage waveform of the isolation transformer and feedback of the waveform data to the control unit. The input terminal of the second voltage transformer is connected to the voltage output terminal of the power source and the aforementioned common output terminal, and its output terminal is connected to the control unit. This allows for real-time acquisition of the output voltage waveform of the power source and feedback of the waveform data to the control unit. These two voltage acquisition loops provide the necessary waveform information for subsequent precise phase adjustment and zero-crossing switching. Simultaneously, the control unit is also communicatively connected to the power source and can send commands to the power source based on the phase information of the isolation transformer acquired by the first voltage transformer. This allows the control unit to adjust the phase of the power source's output voltage to form a predetermined phase difference with the isolation transformer.

[0042] Consistency in relay operating time is crucial for achieving smooth switching. Considering that even relays from the same batch may have slightly different electromagnetic mechanism parameters, the level of the driving voltage directly affects the magnetization time of the relay coil and the contact switching time. Therefore, the control unit in this embodiment also integrates a driving voltage adjustment module corresponding to each relay. This module can provide an adjustable driving voltage to the corresponding relay, thus providing a hardware foundation for calibrating the dynamic characteristics of the relays.

[0043] Based on the aforementioned power supply device, this invention also provides a power supply control method for a testing platform for electricity meters and power consumption acquisition terminals. This method is particularly suitable for scenarios involving the parallel testing of large-scale meters. Taking a 48-meter testing platform as an example, if equipped with a 100VA power source, and powering 48 meters simultaneously using conventional methods, the instantaneous power required to start 48 meters simultaneously would exceed 200VA, far exceeding the power source's capacity and easily leading to start-up failure. The method described in this embodiment can effectively solve this problem.

[0044] The method includes the following steps:

[0045] Step S0: Relay Self-Test Synchronization Phase. This step is performed before the isolation transformer and power source are powered on. Its purpose is to calibrate the switching time of all relays (the time from separation of the common terminal from the normally closed contact to contact of the common terminal with the normally open contact), ensuring consistency and providing a basis for subsequent phase adjustments. Specifically, it includes the following sub-steps:

[0046] Step S0-1: Establish the driving voltage-time interval mapping relationship. The control unit applies multiple different driving voltages to each relay sequentially through its internal driving voltage adjustment module. For each applied driving voltage, the time interval Δt between the moment t2 when the relay separates from the normally closed contact at the common terminal and the moment t3 when the common terminal contacts the normally open contact under that driving voltage is measured and recorded. This time interval is defined as the relay switching time. In this way, a mapping relationship between the driving voltage and switching time is established for each relay.

[0047] Step S0-2: Determine the common switching time. The control unit summarizes the mapping relationship of all relays, analyzes and determines a common time interval ΔT that all relays can achieve. This common time interval can be an intersection value of the switching time ranges of all relays, ensuring that each relay has a driving voltage so that its switching time is exactly equal to ΔT.

[0048] Step S0-3: Determine the operating voltage of each relay. Based on the common time interval ΔT determined in step S0-2, the control unit performs a reverse lookup in the corresponding drive voltage-time interval mapping relationship for each relay to find the drive voltage value that makes the switching time equal to ΔT. Subsequently, the control unit sets this drive voltage as the operating voltage for that relay during subsequent switching operations. At this point, the switching time of all relays in the subsequent switching process is uniformly calibrated to ΔT, thereby eliminating the time deviation caused by individual device differences.

[0049] Step S0-4: Record magnetization time. For each relay, when the control unit applies the operating voltage corresponding to the common time interval ΔT in step S0-3, record the time interval from the moment t1 when the operating voltage is first applied to the moment t2 when the common terminal of the relay actually separates from the normally closed contact. This time interval is defined as the magnetization time of the relay, denoted as ΔT_delay. Due to the slight differences in the electromagnetic characteristics of each relay, the ΔT_delay of different relays may be different. This parameter will be precisely called during subsequent switching processes.

[0050] Step S0-5: Adjust the power source phase. The control unit adjusts the phase of the power source output voltage according to the common time interval ΔT determined in step S0-2. The goal of the adjustment is to create a phase difference of ΔT between the waveform of the power source output voltage and the waveform of the isolation transformer output voltage. For example, if ΔT is 5ms, and for a 50Hz power frequency AC circuit, one cycle is 20ms, then the phase difference corresponding to 5ms is 90°. Therefore, the power source output phase needs to lag the isolation transformer by 90°. This phase adjustment lays the foundation for subsequent "equal phase to zero voltage" switching.

[0051] Step S1, Power-on Startup Phase. The control unit controls all relays to be in an initial de-energized state, keeping the common terminal of each relay closed with its normally closed contact. At this time, although the power source and isolation transformer output power simultaneously, due to the relay contact connection method, only the isolation transformer is actually connected to the power supply circuit. All meters at the installation station draw power from the grid through the isolation transformer and begin startup. The isolation transformer, directly drawn from the grid, has a strong load-bearing capacity and can easily handle the huge surge current generated when all meters are powered on simultaneously, thus avoiding the impact of this surge current on the power source.

[0052] Step S2, Power Supply Switching Stage. After all meters and power sources have completed startup and entered a stable operating state, the control unit begins to execute the equal-phase-zero-voltage time-sharing control strategy, controlling the energization of each relay in a time-sharing manner, so that the power supply source of the corresponding meter is switched sequentially from the isolation transformer to the power source. The specific control process is as follows:

[0053] First, the control unit accurately calculates the time of each voltage zero-crossing point in the future based on the real-time waveform of the isolation transformer output voltage collected by the first voltage transformer. The zero-crossing point here specifically refers to the moment when the isolation transformer output voltage rises from a negative value to 0V or falls from a positive value to 0V.

[0054] Then, the control unit assigns start times to all relays in a preset order. The start time t_action of each relay corresponds to a different zero-crossing point of the isolation transformer output voltage.

[0055] Next, as Figure 2 As shown, for each relay, based on its assigned start time t_action, the time interval ΔT_delay recorded in step S0-4 is called. The time obtained by subtracting ΔT_delay from t_action is taken as the moment t1 when the control unit actually begins applying its corresponding operating voltage to the relay. Thus, from the start of voltage application, after the relay's unique magnetization time ΔT_delay, its common terminal and normally closed contact separate precisely at its start time t_action (i.e., the zero-crossing point of the isolation transformer voltage), achieving the disconnection of the isolation transformer at the zero-crossing point. Immediately afterwards, since the relay's switching time has been calibrated to ΔT, starting from time t3, after another ΔT time, the moment t3 when its common terminal contacts the normally open contact falls precisely at the zero-crossing point of the power source voltage waveform that lags the isolation transformer by ΔT time. At this point, the meter completes a full equal-phase to zero-voltage switching cycle. During the relay switching process, the energy meter will be in a state of no power supply for a very short time. However, since the relay action time is generally less than 30ms, and the energy storage capacitor inside the meter can usually support its operation for more than 200ms after the meter is de-energized. Therefore, this brief power outage will not cause the meter to reset, and the resulting secondary surge current is much smaller than the surge during cold start, and has almost no impact on the power source.

[0056] Each relay completes the switching process sequentially according to a set order and start time, until all meters are switched to power supply. Alternatively, multiple relays can be switched simultaneously as needed to shorten the total switching time.

[0057] Step S3, Testing Phase. After all relays have switched, the power supply for all meters has been completely switched to the power source. The power source provides all meters with the high-precision, high-stability voltage and current signals required for testing. The error detection unit begins operation to perform error detection on the tested energy meter, completing the calibration task.

[0058] Through the above steps, a testing platform with 48 meter positions and a 100VA power source can smoothly start up and complete the testing of all 48 meters without increasing the power source capacity, greatly improving testing efficiency and reducing equipment costs. Throughout the process, because the relay switching time is precisely controlled at the voltage zero-crossing point, contact arcing is effectively suppressed, extending the electrical life of the relays. Simultaneously, the continuity and purity of the voltage waveform before and after switching are ensured, providing a stable power supply foundation for subsequent high-precision testing.

[0059] It should be noted that, as will be apparent to those skilled in the art, the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics thereof. The scope of the present invention is defined by the claims rather than the foregoing description.

Claims

1. A power supply device for a testing platform of an electricity meter and a power consumption acquisition terminal, comprising a power source, an error detection unit, and multiple meter installation stations, and further comprising a standard meter installed at one of the meter installation stations; the voltage output terminal of the power source is used to electrically connect to each meter installation station respectively to supply power to each meter; the error detection unit is used to communicate with the meter under test and the standard meter, characterized in that: The power supply device for the energy meter and power consumption acquisition terminal testing platform also includes an isolation transformer, a control unit, and relays corresponding to the meter installation positions. The voltage input terminal of the isolation transformer is connected to the power grid, and the voltage output terminal is connected to the normally closed contacts of each relay; the voltage output terminal of the power source is connected to the normally open contacts of each relay; the common terminal of the relay is electrically connected to the meter at the corresponding meter installation station. The control unit is electrically connected to each relay and controls each relay to perform switching actions based on the equal phase-zero voltage time-division switching control strategy. The equal-phase-zero-voltage time-sharing control strategy refers to: calculating the time of each zero-crossing point in the future time according to the waveform of the output voltage of the isolation transformer; assigning the start time of action to all relays in a preset order, with the start time of action of each relay corresponding to a different zero-crossing point of the output voltage of the isolation transformer; During switching, let the start time of a relay's operation be t_action. Take the time interval ΔT_delay between the moment t1 when the control unit starts applying the working voltage to the moment t2 when the relay's common terminal separates from the normally closed contact. Use t_action - ΔT_delay as the moment when the control unit starts applying the working voltage. This ensures that the moment t2 when the relay separates from the normally closed contact from the common terminal is exactly the start time t_action, and the moment t3 when the common terminal contacts the normally open contact is exactly the next zero-crossing point of the power source.

2. The power supply device for the electricity meter and electricity consumption data acquisition terminal detection platform as described in claim 1, characterized in that: It also includes a first voltage transformer, whose input terminal is connected to the voltage output terminal of the isolation transformer and whose output terminal is connected to the control unit, for real-time acquisition of the output voltage waveform of the isolation transformer and feedback to the control unit.

3. The power supply device for the electricity meter and electricity consumption data acquisition terminal detection platform as described in claim 2, characterized in that: It also includes a second voltage transformer, whose input terminal is connected to the voltage output terminal of the power source and whose output terminal is connected to the control unit, for real-time acquisition of the output voltage waveform of the power source and feedback to the control unit.

4. The power supply device for the electricity meter and electricity consumption data acquisition terminal detection platform as described in claim 3, characterized in that: The control unit is also communicatively connected to the power source and is used to adjust the phase of the power source output voltage according to the phase of the isolation transformer.

5. The power supply device for the electricity meter and electricity consumption data acquisition terminal detection platform as described in claim 1, characterized in that: The control unit also includes a drive voltage adjustment module corresponding to each relay, which is used to provide drive voltage to the corresponding relay.

6. A power supply control method for an electricity meter and a power consumption data acquisition terminal detection platform, characterized in that: The power supply control method is based on the power supply device for the electricity meter and the electricity consumption acquisition terminal detection platform as described in any one of claims 1 to 5, and includes the following steps: Step S1, Power-on start-up stage: The control unit controls all relays to be in a de-energized state, keeping the common terminal of each relay closed with the normally closed contact, and the meters at each meter installation station draw power from the power grid through the isolation transformer and start up. Step S2, Power Supply Switching Stage: After all meters and power sources have started up, the control unit begins to execute the equal phase-zero voltage time-sharing switching control strategy, controlling each relay to be energized and activated in a time-sharing manner, so that the power supply source of the corresponding meter is switched from the isolation transformer to the power source; Step S3, Detection Stage: After all relays have switched, the power source provides the voltage and current signals required for detection to all meters, and the error detection unit performs error detection on the tested energy meter.

7. The power supply control method for the energy meter and power consumption acquisition terminal detection platform as described in claim 6, characterized in that, It also includes step S0, which is executed before step S1 begins: Step S0, Relay Self-Test Synchronization Stage: The control unit adjusts the drive voltage of each relay so that the time it takes for all relays to separate from the normally closed contact at the common terminal and to contact the normally open contact at the common terminal is consistent when they operate.

8. The power supply control method for the detection platform of the electricity meter and electricity consumption acquisition terminal as described in claim 7, characterized in that, Step S0 specifically includes: Step S0-1: The control unit sequentially applies multiple different driving voltages to each relay, measures and records the time interval Δt between the time t2 when the common terminal separates from the normally closed contact and the time t3 when the common terminal contacts the normally open contact under each driving voltage, and establishes a driving voltage-time interval mapping relationship for each relay. Step S0-2: The control unit determines a common time interval ΔT that can be achieved by all relays based on the mapping relationship of all relays; Step S0-3: The control unit searches for the corresponding driving voltage for each relay in reverse according to the common time interval ΔT, and uses the driving voltage as the working voltage for the subsequent operation of the relay, so that the switching time of all relays in the subsequent switching process is ΔT.

9. The power supply control method for the energy meter and power consumption acquisition terminal detection platform as described in claim 8, characterized in that, Step S0 also includes: Step S0-4: Adjust the phase of the power source according to the common time interval ΔT, so that the time value corresponding to the phase difference between the power source and the isolation transformer is equal to the common time interval ΔT.

10. The power supply control method for the detection platform of the electricity meter and electricity consumption acquisition terminal as described in claim 9, characterized in that: In step S0, for each relay: the moment when the control unit starts applying the working voltage corresponding to the common time interval ΔT is recorded as t1, and the time interval ΔT_delay from t1 to t2 is recorded; The equal-phase-zero-voltage time-sharing control strategy described in step S2 refers to: calculating the time of each zero-crossing point in the future time based on the waveform of the output voltage of the isolation transformer; assigning the start time of action to all relays in a preset order, with the start time of action of each relay corresponding to a different zero-crossing point of the output voltage of the isolation transformer; During switching, let the start time of a certain relay's action be t_action, and take the time interval ΔT_delay recorded by the relay in step S0. Take the time t_action-ΔT_delay as the time when the control unit starts to apply the working voltage, so that the time t2 when the relay separates from the normally closed contact from the common terminal is exactly the start time t_action, and the time t3 when the common terminal contacts the normally open contact is exactly the next zero-crossing time of the power source.

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