The 33rd China International Exhibition on Electric Power Equipment and Technology
Shanghai International Energy Storage Technology Application Expo / Hydrogen Energy Expo
Power instrumentation and meters are the measurement devices that quantify electrical parameters throughout the power system, from generation to end-use consumption. They encompass a wide range of products: energy meters (single-phase and three-phase, for billing and sub-metering); power quality analysers (measuring harmonics, voltage sags, flicker, and unbalance); power transducers (converting electrical quantities to analogue or digital signals for SCADA and control systems); current and voltage transformers (instrument transformers that scale high-voltage, high-current signals to safe measurement levels); digital panel meters and power monitors; and smart meters with communication capabilities for advanced metering infrastructure (AMI). Accurate power measurement is fundamental to grid operation, energy billing, power quality management, and energy efficiency programmes. China's national smart meter rollout — one of the largest AMI deployments in the world — has driven massive demand for smart metering technology.
5 Key Questions About Power Instrumentation & Meters
Energy meters measure the total electrical energy consumed or generated over time (kWh, kVAh, kVArh), primarily for billing and energy accounting purposes. Modern smart meters also record interval data (typically 15-minute or 30-minute readings) and communicate via AMI networks. Power quality analysers measure the dynamic characteristics of the power supply — voltage sags and swells, harmonics, flicker, frequency variations, transients, and unbalance — to diagnose power quality problems affecting sensitive equipment. Some advanced meters combine both functions, providing energy measurement and power quality monitoring in a single device.
Current transformers (CTs) and voltage transformers (VTs) are the interface between high-voltage power circuits and low-voltage measurement and protection equipment. CTs produce a secondary current (typically 1 A or 5 A) proportional to the primary current, enabling safe measurement of currents from hundreds to tens of thousands of amperes. VTs produce a secondary voltage (typically 100 V or 110 V) proportional to the primary voltage, enabling measurement of voltages from 1 kV to 1,100 kV. Accuracy class requirements for metering (Class 0.2S or 0.5S) are more stringent than for protection (Class 5P or 10P), and metering and protection cores are typically separate windings on the same core.
Smart meters use a variety of communication protocols depending on the AMI architecture: power line communication (PLC) using OFDM modulation (PRIME, G3-PLC, or China's proprietary HPLC standard) for last-mile communication over the distribution network; RF mesh networks using 802.15.4g or proprietary protocols; GPRS/4G/5G cellular for direct communication with the utility head-end system; and NB-IoT for low-power wide-area network connectivity. China's State Grid has standardised on HPLC (High-speed Power Line Communication) for its smart meter AMI rollout, with hundreds of millions of HPLC-enabled meters deployed.
Industrial facilities use power quality measurement to diagnose problems affecting production equipment: voltage sags causing motor trips and PLC resets; harmonics from variable speed drives overheating transformers and cables; voltage unbalance reducing motor efficiency and life; and transients damaging sensitive electronics. Power quality analysers are installed at the point of common coupling (PCC) with the utility and at critical loads to characterise the power supply quality and identify the source of disturbances. Measurement data supports decisions on power quality mitigation equipment — UPS systems, active filters, voltage conditioners — and provides evidence for utility compensation claims.
Revenue-grade energy meters must meet accuracy class requirements specified in IEC 62053 (AC electricity metering equipment) or the equivalent Chinese standard GB/T 17215. Class 0.2S meters (used for high-voltage metering at large industrial and utility customers) must measure active energy with an error not exceeding 0.2% at rated current and 0.5% at 5% of rated current. Class 1 meters (used for residential and small commercial customers) allow errors up to 1% at rated current. Meters must be type-tested by an accredited laboratory and are subject to periodic in-service verification by the utility or a metrology authority.
Key Takeaways
Power instrumentation and meters are the measurement foundation of the power system, enabling accurate energy billing, grid monitoring, power quality management, and energy efficiency programmes. China's massive smart meter rollout and the growth of distributed energy resources are driving strong demand for advanced metering and power quality measurement technology. EP Shanghai showcases the full spectrum of power measurement products from leading Chinese and international manufacturers.
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