Overview
IEC 61683:1999 - "Photovoltaic systems - Power conditioners - Procedure for measuring efficiency" is an IEC standard that defines a standardized, factory-level procedure to measure the electrical efficiency of power conditioners (inverters/DC–DC converters) used in both stand‑alone and utility‑interactive photovoltaic (PV) systems. The standard focuses on direct measurement of input and output power for devices that produce a stable a.c. voltage at constant frequency or a stable d.c. voltage. An isolation transformer is included where applicable. The standard explicitly excludes indirect items such as maximum power‑point tracking (MPPT) accuracy.
Key topics and requirements
- Scope and definitions: Defines terms such as rated output efficiency, partial output efficiency, energy efficiency, no‑load loss and standby loss.
- Test conditions:
- Ambient temperature: 25 °C ± 2 °C (must be recorded).
- Output voltage and frequency at manufacturer’s nominal values.
- Input voltages: tests at manufacturer’s minimum rated input, nominal/average input, and 90% of maximum input (battery‑input units may be tested at nominal only).
- Record input/output ripple and distortion (THD) for every measurement.
- Load matrix: Efficiency measured across a matrix of power levels (5%, 10%, 25%, 50%, 75%, 100%, 120% of rated VA as applicable) and load types:
- Resistive (unity PF)
- Reactive loads at PF = 0.25 (or minimum), 0.5, 0.75
- Non‑linear loads (specified THD ≈ 80% ± 5%) at 25% and 50% of rated VA
- Complex combinations (non‑linear + reactive)
- Measurements and calculations:
- Direct input/output power measurements and standard formulas for rated and partial output efficiency; auxiliary input power must be included.
- Energy efficiency and efficiency tolerances; guidance for no‑load and standby loss measurement.
- Test circuits and documentation: Specifies required test circuits, measurement procedures, and reporting formats (tabular/graphical). Informative annexes cover power conditioner descriptions, conversion factors and weighted‑average energy efficiency.
Applications and users
IEC 61683 is intended for:
- PV inverter and power conditioner manufacturers - to verify and publish efficiency claims.
- Test laboratories and certification bodies - for consistent, repeatable efficiency testing and accreditation.
- PV system designers and specifiers / procurement teams - to compare device efficiencies for system sizing, yield estimates and economic modeling.
- Research and development teams - for benchmarking conversion performance under defined loads and input conditions.
Keywords: IEC 61683, photovoltaic, power conditioners, inverter efficiency, efficiency measurement, PV systems, energy efficiency testing, MPPT, no‑load loss, standby loss.
Related standards
- IEC 60146‑1‑1:1991 (semiconductor converters - basic requirements) - normative reference.
- IEC 60050, IEC 60027, IEC 60417, IEC 60617 - referenced for terminology and symbols.