Overview
Solar power and battery storage have become central to the energy transition, and both depend on power electronics that convert and monitor energy efficiently and safely. A solar inverter must track the maximum power point of the panels, deliver a clean grid-compliant output and protect itself against faults, while a storage converter must switch in both directions with high round-trip efficiency. Behind every one of those functions is an accurate, isolated measurement of current and voltage. LEM transducers provide that measurement, and BeiLuo supplies them with genuine traceability and FAE support.
Current Sensing in a Solar Inverter
A string inverter begins with a DC-DC boost stage that implements maximum power point tracking, followed by a DC-AC inverter stage that feeds the grid. Both stages need current feedback. The boost stage measures the string current to track the panel operating point, and the inverter stage measures the output current to regulate the grid feed. Because these currents sit on a high-voltage DC bus, isolation is essential to protect the controller. Compact open-loop sensors such as the HLSR20-P fit the dense string board with a single +5 V supply and a direct voltage output, while the wide -40 °C to +105 °C range suits outdoor enclosures.
Maximum Power Point Tracking
Maximum power point tracking squeezes the last watt from every panel by continuously adjusting the operating point under changing irradiance and temperature. The tracking algorithm depends on an accurate, low-noise current signal, because it moves the operating point in small steps and reads the resulting change in power. A sensor with low offset drift and good signal-to-noise performance helps the tracker hold the true maximum power point, which directly increases energy harvest.
Storage Converters and Bidirectional Current
A battery energy-storage converter charges and discharges, so the same power stage carries current in both directions. Measuring that current accurately in both directions is essential for state-of-charge estimation, for protection and for control. A closed-loop transducer such as the LA55-P is well suited because it measures bipolar current with low offset, which matters when the current crosses zero during the transition between charge and discharge. Because the converter runs continuously, the sensor must hold its accuracy across the whole operating range, not only at peak current.
Voltage Sensing for the DC Link
Solar and storage converters regulate the DC-link voltage and must monitor it for control and protection. The LV25-P measures voltage up to 500 V on a compact PCB, using an external resistor to set the range, and its isolation protects the controller. For higher bus voltages, the panel-mount DVL range and the compact DVC 1000-P extend isolated measurement to 1000 V and above with excellent accuracy, which suits large central inverters and high-voltage storage systems.
Designing for Outdoor Reliability
Solar and storage equipment must survive wide temperature swings, humidity and, in some cases, dust. Plan the sensor for the highest ambient it will see, keep the primary conductor geometry as the factory calibration expects, and protect the signal path from switching noise. Place the current sensor close to the power stage to keep the primary path short, and screen the secondary connection to the ADC. For voltage sensing, respect the creepage and clearance distances for the working voltage and confirm the isolation rating against the system voltage class.
Selection and Supply
Selection starts with the current and voltage levels of the string, bus or battery, then narrows by isolation, accuracy, temperature range and mounting. Match the current rating with headroom for transients, and choose the voltage-sensor range with margin above the worst-case bus. BeiLuo keeps mainstream LEM current and voltage transducers in regional stock, ships them with import declaration, certificate of origin and RoHS documents, and supports selection, resistor sizing and layout with an in-house FAE team. From a rooftop string inverter to a grid-scale storage system, our engineers help you choose the sensing that keeps the converter accurate, efficient and safe.