Technical Analysis of ZXDN-306 Three-phase Multi-function Meter InspectionDevice

Abstract

The three-phase energy meter verification device serves as core standard equipment within electric power metrology systems, undertaking the critical task of accuracy testing and performance verification for electricity meters. This paper introduces the ZXDN-306 three-phase multi-function meter inspection device, elaborates on its design concept, structural characteristics, core functional modules and comprehensive technical specifications. The analysis targets metrology engineers and laboratory technical personnel, offering a reference for equipment selection, test application and performance evaluation in meter verification laboratories.

1. Product Overview

The ZXDN-306 three-phase multi-function meter inspection device is developed in strict compliance with relevant national standards and regulations. Drawing on over ten years of manufacturing experience in programmable three-phase energy meter verification equipment, this electronically controlled standard source system is optimized to adapt to calibration requirements of various three-phase energy meters.

The equipment supports verification for single-phase and three-phase energy meters with accuracy class 0.2 and below, including sinusoidal reactive power meters. With sophisticated workmanship, comprehensive testing functions and stable electrical performance, it is widely applicable in metrology institutes, power grid calibration laboratories and meter manufacturing factories.

2. Core Structural & Functional Features

2.1 Mechanical Structure & Human-machine Interface

The device adopts either split or integrated layout. The hanging frame is constructed from special aluminum alloy, paired with fireproof composite table panels for good structural rigidity and neat appearance. A 7-inch color LCD human-machine interface equipped with embedded RAM system delivers rich visualized testing data with intuitive operation. Each meter position is fitted with a 6-digit LED multi-function display, which can real-time show basic error values, clock frequency and various test flags of every test station.

2.2 High-precision Signal Generation System

The signal source applies Direct Digital Synthesis (DDS) technology, built upon large-scale CPLD and embedded RAM architecture. It realizes 36000-level phase modulation, 12-bit D/A waveform synthesis and 16-bit D/A amplitude modulation output. This design guarantees excellent performance: high output stability, fine adjustment resolution and low waveform distortion.

Power amplification adopts PWM modulation power amplifier, featuring large output capacity, low heat generation and up to 90% energy efficiency. Voltage and current outputs support soft start and soft stop. Built-in multi-layer protection covers voltage output short-circuit alarm and current output open-circuit protection, significantly improving operational reliability.

2.3 Meter Wiring & Signal Acquisition Design

Energy meter current terminals adopt quick crimp aluminum alloy junction boxes; smart meter crimp boxes are available as optional configuration. Each station integrates multi-channel protected pulse switching terminals: four pulse channels, one RS485 channel and one multi-function channel. The hardware protection circuit prevents accidental high voltage intrusion and equipment damage, supporting one-time wiring and automatic channel switching.

Every meter position is equipped with open-circuit detection function, which automatically identifies and indicates empty meter positions. Automatic short-circuit for vacant positions can be configured optionally. A tariff control detection module is embedded for local and remote tariff switching tests. It can check the switch performance of relays built into smart meters and measure output signals of external relays.

2.4 Synchronous Clock & Communication Configuration

The standard configuration includes ZXT10 high-precision standard clock with 3×10⁻⁸ crystal oscillator to complete meter clock error testing. ZXGT10 GPS clock timer is an optional upgrade. Multi-serial communication is supported. Each test station has an independent RS485 communication port; optional serial server enables parallel multi-station communication. A three-dimensional adjustable multi-function photoelectric sampler is reserved for each station (optional), reliably capturing black-mark signals from mechanical meters and strobe pulses of electronic energy meters.

2.5 Optional Extended Modules & Software

A carrier communication switching box with built-in mainstream domestic carrier controllers can be equipped on demand. Supporting hierarchical verification management software adopts power-off protection and advanced multi-thread programming technology to ensure stable parallel communication of multiple meter stations.

3. Key Technical Indicators

3.1 Accuracy Class

The equipment supports optional accuracy grades: 0.02, 0.03, 0.05 and 0.1.

3.2 Voltage & Current Output

Output Voltage Per-phase selectable voltage levels: 57.7 V, 100 V, 220 V, 380 V. Adjustable range: 0 ~ 120% rated value, continuous adjustment. Adjustment resolution: 10%, 1%, 0.1%, 0.01%.

Output Current Available current gears: 0.005 A, 0.025 A, 0.1 A, 0.25 A, 0.5 A, 1 A, 2.5 A, 5 A, 10 A, 20 A, 50 A, 100 A. Adjustable range: 0 ~ 120% rated value, continuous adjustment. Adjustment resolution: 10%, 1%, 0.1%, 0.01%.

3.3 Output Capacity

The equipment can be customized with 3, 6, 12, 16, 20, 24, 32, 48 meter positions. The voltage and current output capacity varies with station quantity: For instance, the 3-station version provides 150 VA voltage output and 300 VA current output; the maximum 32-station model reaches 1000 VA voltage output and 2000 VA current output.

3.4 Stability & Waveform Quality

Output voltage and current stability within 120 seconds: 0.02 / 0.03 class: ≤0.02%; 0.05 / 0.1 class: ≤0.05%. Total harmonic distortion of output voltage and current: 0.02 / 0.03 class ≤0.3%; 0.05 class ≤0.5%; 0.1 class ≤1%.

3.5 Phase, Frequency and Synchronization Specifications

Three-phase symmetry deviation: better than 120° ±0.3°

Frequency range: 45 Hz ~ 65 Hz, adjustment resolution: 0.01 Hz

Phase shift range: −180.0° ~ +180.0°, adjustment resolution: 0.01°

Standard crystal stability: ≤3×10⁻⁸ /s

3.6 Other Parameters

Indicating meter accuracy: voltmeter & ammeter 0.2%; phase meter ±0.1°; frequency meter ±0.1 Hz. Power supply: 3 × 220 V ±10%, 50 Hz. Operating environment: nominal temperature 20 ℃, allowable deviation ±5 ℃, relative humidity ≤85%.

4. Application Prospects

As smart grid construction continuously advances, higher requirements are raised for the verification precision, testing efficiency and function scalability of energy meter calibration equipment. The ZXDN-306 multi-function meter inspection device integrates high-precision signal source, multi-channel automatic switching, tariff control testing, clock error detection and multi-type signal acquisition. It satisfies comprehensive verification requirements for modern multi-function smart energy meters. The flexible station-number configuration and abundant optional modules enable customized deployment for small laboratories and large centralized verification workshops.

5. Conclusion

The ZXDN-306 three-phase multi-function meter inspection device adopts mature DDS signal generation and PWM power amplification technology. It combines high metrological accuracy, complete test functions and systematic protection design. This equipment can meet routine verification and type evaluation tests of single-phase and three-phase energy meters. For metrology technical staff, mastering its technical parameters and functional characteristics helps standardize meter verification processes, improve test efficiency and guarantee the traceability of electric energy measurement values.

 GDZX is a manufacturer of power detection equipment, offering a diverse range of products with comprehensive models and providing professional technical support. Contact us at +86-27-6552607 or +86-17396104357.Website: http://en.gdzxdl.com/