What this page solves

This page bridges the gap between a power-stage schematic and a grid-tied PV inverter controller board, focusing on sensing, control and gate-drive hooks instead of power topology details.

The target use case is a 10–50 kW three-phase grid-tied PV inverter where the mechanical layout and power stage are already defined, but the control board still needs to be architected. Design work must cover how phase currents and voltages are sensed with isolated ΣΔ or amplifier AFEs, how the DC-link is monitored and protected, how the controller locks to the grid with a robust PLL, and how MCU or SoC resources connect to gate drivers and protection paths.

The focus stays on the controller board: AFEs and isolated ΣΔ current sensing, DC-link monitoring, grid PLL and control loops, gate drivers and fault hooks. Topics such as detailed power device topology, long-term energy management strategy or plant-level scheduling are handled by other pages in the Smart Grid cluster, including Battery PCS for Grid, SVG / STATCOM and Microgrid Controller.

By the end of this page, the controller board can be planned around four concrete decisions:

• How to implement isolated ΣΔ or amplifier-based current and voltage sensing that serves both FOC control and protection.
• How to monitor the DC-link, define over-voltage / under-voltage thresholds and connect them to fast protection paths.
• How to design the grid-synchronization PLL and integrate it with the control loops.
• How to choose MCU / SoC features and gate driver interfaces so that PWM, protection and communication all fit on a realistic controller PCB.

System context and non-overlap with other pages

A grid-tied PV plant can be viewed in three layers. At the bottom, power and energy hardware converts DC from PV and storage into AC power, including PV inverters, battery PCS units, SVG / STATCOM equipment and HVDC interfaces. In the middle, device-level controllers run control loops, gate drivers and protection for each power converter. At the top, grid and EMS controllers coordinate multiple DER assets, enforce plant-level limits and interact with SCADA or microgrid software.

This page focuses strictly on the middle layer for a PV inverter: the controller board that implements current and voltage sensing, PLL-based grid synchronization, real-time control loops and gate-driver and protection hooks. Plant-level scheduling, optimization and dispatch logic are handled by pages such as Microgrid Controller and DR / DER Aggregator, while detailed bidirectional power-flow management with batteries belongs to Battery PCS for Grid, and standalone reactive-power or harmonic compensation is covered by SVG / STATCOM.

Control architecture of a grid-tied inverter

A grid-tied PV inverter controller must coordinate DC-link voltage regulation, AC output current control and grid-synchronization in a single coherent architecture. The control board sits between measurement AFEs, power-stage gate drivers and grid-facing protection and follows a repeatable pattern: measurement and transformation, control loops and PWM generation.

A typical design uses an outer DC-link voltage loop that determines power flow and inner d-q current loops that shape the three-phase grid currents. These loops depend on tightly aligned measurements from isolated AFEs and ADCs, on a stable PLL that provides the grid angle and on a clear separation between fast hardware protection paths and slower software supervision logic.

Current and voltage control loops

In most grid-tied PV inverters, an outer DC-link voltage loop commands the overall active power, while inner AC current loops regulate the three-phase output in the d-q frame. The DC-link loop runs at a lower bandwidth and keeps the DC bus within limits, and the d-q current loops run faster to shape the grid current and enforce power-factor or reactive power targets.

• The DC-link voltage controller sets an active-power or d-axis current reference that the inner current loops track.
• d-axis current usually controls active power, while q-axis current manages reactive power or power factor in accordance with grid-code and plant-level commands.
• Loop bandwidths are selected so that the voltage loop is clearly slower than the current loops, avoiding interaction and oscillation.

Measurement and ADC timing

Reliable control depends on predictable timing between sampling instants and PWM updates. Phase currents, grid voltages and DC-link voltage should be sampled at well-defined points in the PWM cycle so that d-q transformations and PI controllers see consistent data with minimal jitter and delay.

• Current and voltage ADC triggers are usually aligned with PWM carrier midpoints or quiet windows to avoid sampling during switching edges.
• ΣΔ modulators and digital filters must be configured so that their decimated outputs are synchronized with the control-cycle and consistent across all phases.
• Multi-channel ADC and ΣΔ interfaces should support simultaneous sampling or deterministic skew so that d-q transformation uses coherent phase data.

Hardware and software protection paths

Protection is implemented through two complementary paths. A fast hardware path reacts directly to severe events such as short-circuit or extreme DC-link over-voltage and forces the gate drivers into a safe state. A slower software path supervises longer-term stress, temperature margins and abnormal grid conditions, applies derating and decides when to reconnect.

• Hardware comparators or built-in gate-driver protection inputs handle rapid over-current, desaturation and extreme over-voltage events with minimal delay.
• Software monitors temperatures, frequency deviations, voltage sags and communication state, adjusting power or commanding controlled shutdown when needed.
• Both paths rely on the same sensing chain, but thresholds, timing and outputs are tuned differently for safety-critical versus operational decisions.

Isolated AFE and sigma-delta current sensing

Most modern grid-tied PV inverters rely on shunt-based isolated current sensing using sigma-delta modulators or isolated amplifiers. This approach delivers the accuracy and bandwidth needed for FOC and protection, while providing galvanic isolation and high common-mode transient immunity in noisy power stages.

Why shunt plus isolated AFE or sigma-delta is common

Shunt resistors combined with isolated AFEs or sigma-delta modulators offer a compact and precise way to measure phase currents and DC-link currents. The sensing elements sit close to the power stage, while digital or robust analog signals cross the isolation barrier to the controller.

• High accuracy and low drift support both control performance and energy-metering style monitoring.
• Galvanic isolation and high CMTI ratings withstand fast dv/dt from modern IGBTs and SiC switches.
• Digital sigma-delta streams or differential analog outputs are less sensitive to common-mode noise than low-level single-ended signals.

Typical current-sensing signal chains

There are two main options for shunt-based isolated current sensing in a PV inverter controller: sigma-delta modulators with digital filtering in the MCU or SoC, and isolated amplifiers that feed an on-chip ADC. Both use shunts placed at low-side, high-side or phase nodes, chosen according to topology and layout.

• Sigma-delta modulator chain: shunt → sigma-delta AFE → digital isolation or LVDS link → sigma-delta filters and decimation in the controller.
• Isolated amplifier chain: shunt → isolated amplifier or differential AFE → scaled analog signal → ADC inside the controller.
• Hall or CT-based sensing remains useful for very high currents or retrofit designs, but typically delivers lower precision than shunt-based isolated AFEs.

Key parameters and channel planning

Current-sensing devices and AFEs should be selected based on immunity to inverter switching noise, linearity and effective resolution across the full current range, and the ability to synchronize all channels with the control cycle. Channel count must cover three-phase currents, DC-link current and any leakage or ground-fault sensing used by protection logic.

• CMTI rating suitable for fast-switching devices, often tens of kV/µs, to prevent false outputs under high dv/dt.
• Linearity, INL and effective resolution that preserve accuracy at low and nominal currents.
• Bandwidth and latency compatible with the chosen control-loop bandwidth and switching frequency.
• Synchronous sampling or channel-alignment features that allow all phase currents to be processed coherently for d-q control.
• Isolation rating, creepage and package options compatible with safety standards and PCB layout constraints.

DC-link monitoring and protection

The DC-link capacitor is the energy buffer between the PV source, the power stage and the grid. Reliable sensing and protection around this node are essential, because cloud transients, grid disturbances and interactions between parallel inverters can push the DC bus towards unsafe over-voltage or deep undervoltage.

Typical failure scenarios include fast irradiance swings causing DC-link overshoot, and backfeed from other inverters or battery converters when one unit trips or changes operating mode. A well-designed monitoring scheme combines a precise sensing path for control and logging with a fast hardware protection path that can shut down the power stage before components are overstressed.

DC-link voltage sensing path

DC-link voltage sensing usually starts with a resistor divider at the DC bus, followed by an isolated amplifier or sigma-delta AFE that transfers a scaled representation of Vdc into the controller domain. The resulting signal is digitised by an ADC or sigma-delta filter block and feeds the DC-link control loop, protection thresholds and diagnostic functions.

• The resistor divider and isolation stage must tolerate the maximum DC-link voltage plus over-voltage margin, while limiting dissipation and leakage currents.
• ADC resolution should allow discrimination between nominal voltage, allowed tolerance band and over-voltage threshold with comfortable margin.
• Sampling rate is chosen to match the control cycle and expected transient behaviour, typically in the kHz range rather than at switching frequency.

Over-voltage, under-voltage and hardware shutdown

In addition to the measurement chain, a dedicated protection path supervises the DC-link with independent comparators or integrated AFE thresholds. This path generates fast over-voltage and under-voltage signals that can reach gate drivers or fault latches directly, bypassing software and avoiding delays caused by firmware execution or communication.

• Over-voltage thresholds protect DC-link capacitors, semiconductors and insulation; the hardware trip is set slightly above the maximum allowed operating voltage.
• Under-voltage thresholds prevent loss of control margin and excessive current at low DC-link levels, and can force a controlled shutdown or inhibit restart.
• Hardware OVP and UVP outputs typically feed gate-driver shut-down pins, a central fault latch or a safety monitor IC, ensuring a deterministic reaction time.

Precharge, discharge and topology considerations

DC-link voltage sensing also guides precharge and discharge functions. During precharge the controller monitors Vdc to decide when to bypass the precharge resistor or close the main contactor; during discharge it verifies that the DC-link has fallen to a safe level before allowing access or re-energisation.

Two-level and three-level topologies differ in where sampling nodes are placed, especially when capacitors are split or tied to neutral points. However, the essential requirement remains the same: measure an accurate representation of the effective DC-link voltage that defines device stress and control headroom, and apply consistent protection thresholds based on that value.

Grid synchronization and PLL

A phase-locked loop is the reference point for all grid-tied control in a PV inverter. By tracking the grid voltage phase, frequency and magnitude, the PLL provides the angle and timing needed to transform three-phase quantities into the d-q frame and to align current injection with grid-code and plant requirements.

In weak or distorted grids the PLL must react quickly enough to follow legitimate frequency and phase changes, while rejecting harmonics and noise that would otherwise disturb control loops. Design choices around structure, bandwidth and implementation details have a direct impact on stability, ride-through behaviour and the ability to coordinate with higher-level microgrid controllers.

PLL role in grid-tied control

The PLL takes three-phase grid voltages and produces a continuous estimate of grid angle and frequency. This angle defines the orientation of the d-q reference frame used by the current controllers and determines how active and reactive currents map into physical phase currents and voltages.

• The PLL’s angle output is used by Clarke and Park transforms so that d-axis current mainly controls active power and q-axis current manages reactive power or power factor.
• Grid frequency estimates from the PLL support protection decisions, including over-frequency, under-frequency and loss-of-synchronism detection.
• In multi-inverter or microgrid scenarios, PLL behaviour influences how cleanly units share power and how well they maintain phase alignment during transients.

Implementation on MCU or SoC

Digital PLLs for three-phase inverters are often based on αβ or d-q structures. Three-phase grid voltages are sampled, transformed into stationary or rotating reference frames and passed through a phase detector, loop filter and numerically controlled oscillator. The MCU or SoC runs these blocks at a fixed rate, typically synchronised with the control cycle.

• αβ PLL and d-q PLL structures both rely on balanced three-phase sampling; the choice often depends on controller resources and preferred tuning methods.
• Loop bandwidth must be wide enough to track real frequency changes and grid disturbances, but narrow enough to filter harmonics and measurement noise.
• Implementation details such as sample rate, numerical resolution and saturation handling are critical in fixed-point controllers and high-distortion environments.

Interaction with protection and ride-through

PLL outputs feed protection and ride-through logic alongside control loops. The inverter needs to know when the PLL is locked, how far grid frequency and voltage have drifted from nominal and whether voltage dips or distortions are temporary or indicative of a fault. These signals shape decisions about staying connected, derating or tripping.

• Locked or unlocked status from the PLL is used to gate synchronised connection and reconnection to the grid.
• Frequency deviation and phase error outputs can trigger derating or controlled shutdown when limits specified by standards or plant rules are exceeded.
• In weak or heavily distorted grids, PLL tuning affects ride-through margins and the robustness of voltage sag and swell handling.

Gate driver selection and isolation

The gate-drive stage sits between the controller board and the power module, translating logic-level PWM signals into high-current gate pulses that safely switch IGBTs or SiC MOSFETs. Correct selection of isolated gate drivers and channel arrangement directly affects switching losses, EMI, short-circuit robustness and long-term reliability in a grid-tied PV inverter.

From the controller perspective, the task is to define clear requirements for CMTI, drive current, propagation-delay matching, UVLO behaviour and protection features such as desaturation detection and soft shutdown. The physical pairing of specific drivers and power modules can then follow these requirements without changing the control architecture.

Role split between controller, driver board and power module

A PV inverter typically separates responsibilities across three levels. The controller board generates PWM patterns and manages protection and diagnostics. The driver board provides galvanic isolation, gate-drive currents and local protection. The power module handles energy conversion and determines required gate voltages and short-circuit withstand capabilities.

• The controller board focuses on control algorithms, PWM timing and high-level fault handling, exposing clean digital interfaces towards the driver board.
• The driver board translates digital control into gate currents, implements UVLO and desaturation detection, and routes fault feedback back to the controller.
• The power module defines gate-voltage requirements, short-circuit ratings and creepage/clearance constraints, which the driver and layout must respect.

Key parameters for isolated gate drivers

Isolated gate drivers for SiC- and IGBT-based PV inverters are defined by a small set of critical parameters. These determine whether the driver can withstand fast switching edges, drive the required gate charge and maintain timing alignment across phases and devices.

• Common-mode transient immunity (CMTI) sets the tolerance to dv/dt at the switch node; SiC applications often require tens of kV/µs to avoid false turn-on or loss of control.
• Gate-drive current must charge and discharge the total gate charge within the allowed switching time, balancing switching losses, dv/dt and EMI.
• Propagation delay and channel-to-channel matching influence dead-time margins and current sharing in multi-phase or parallel-module arrangements.
• Undervoltage lockout (UVLO) thresholds on both high-side and low-side supplies prevent partial enhancement and protect devices when gate supplies are unstable.

Protection functions: desaturation, soft shutdown and short-circuit handling

Integrated protection features in the gate driver are the first line of defence against short circuits and abnormal switching. Desaturation detection monitors device voltage during conduction, while soft shutdown profiles the turn-off so that short-circuit currents fall without inducing excessive over-voltage or oscillation.

• Desaturation detection senses a rising collector–emitter or drain–source voltage, indicating that the power device can no longer sustain the commanded current.
• Soft shutdown reduces gate voltage in a controlled way when a fault is detected, limiting di/dt and dv/dt while still bringing the device to a safe off state.
• Fault outputs from the driver return a clean digital indication to the controller, allowing coordinated fault logging, power derating or controlled restart.
• Detailed coordination between short-circuit ratings, energy limits and gate-driver behaviour is handled in the power-module and topology-focused design stage.

Isolation options and channel mapping

Several isolation technologies are available for gate drivers, including magnetic, capacitive and optical coupling. Each technology offers different trade-offs in CMTI, lifetime, integration level and cost, but all must satisfy insulation and creepage requirements at the inverter’s DC-link voltage.

Channel mapping can follow either a centralised or distributed pattern. A centralised driver board may host multiple channels for a complete bridge or multi-phase stage, whereas distributed drivers place smaller modules close to each power device. Centralised layouts simplify power-supply distribution and layout control, while distributed layouts minimise loop inductance and improve signal integrity.

MCU and SoC control-platform requirements

The controller platform for a PV inverter must combine suitable peripherals, compute performance and safety features in one device. High-resolution PWM generators, synchronous ADC triggering and sigma-delta interfaces support precise control, while communication and security resources connect the inverter to plant-level systems and protect firmware and data.

Different device classes, ranging from general-purpose MCUs to motor-control MCUs and digital power SoCs, can satisfy these requirements. The choice depends on the required number of phases, control complexity, grid-code features, communication integration and long-term product roadmap.

Peripheral set for grid-tied PV inverter control

Peripherals determine how cleanly the controller can interact with sensing and actuation stages. For PV inverters, the focus lies on PWM capabilities, correctly triggered and aligned ADC or sigma-delta sampling, and interfaces to external position or communication devices where required.

• High-resolution PWM units with dead-time control, synchronised update and fast trip inputs for clean interaction with isolated gate drivers.
• ADCs that support synchronous triggers, simultaneous sampling and programmable sampling windows for current, voltage and DC-link sensing.
• Sigma-delta interfaces or high-speed serial ports for receiving isolated sigma-delta streams from current and voltage modulators.
• Position and feedback interfaces such as encoder or Hall inputs if the same controller also manages motor drives or integrated motion functions.
• Communication interfaces including CAN, RS-485, Ethernet and UART for connection to plant controllers, gateways and monitoring systems.

Compute performance and memory requirements

Computational capacity defines how many control tasks and grid-code features can run in a single device. The controller must update current and voltage loops, execute the PLL, handle harmonic mitigation and manage communication stacks and diagnostics within strict cycle times.

• A math-capable core, often with floating-point support, simplifies implementation of FOC, PLL and harmonic filters at the desired switching frequency.
• Sufficient flash memory is required for control firmware, communication protocols, grid-code routines and event-log storage.
• RAM must hold control-loop states, filter coefficients, communication buffers and data for diagnostics, with margin for future feature growth.
• Digital power SoCs may provide tightly coupled accelerators for PWM updates or power calculations, further increasing headroom for advanced features.

Safety, robustness and lifecycle support

Safety-related features define how robustly the controller copes with software faults, transient conditions and potential cybersecurity risks. These capabilities may be critical for compliance with safety standards and for coordination with dedicated cybersecurity or safety modules in the system.

• Independent watchdog timers, potentially including window watchdogs, supervise firmware execution and trigger controlled recovery on failure.
• Secure boot mechanisms help ensure that only authorised firmware images can run, forming a foundation for trusted system start-up.
• Dual-core or lockstep architectures add diagnostic coverage for functional safety projects targeting higher integrity levels.
• More advanced cryptography and key-management functions, often offloaded to a dedicated security module, are covered in grid cybersecurity topics.

Protection hooks and grid-code features

A PV inverter controller is often required to comply with anti-islanding, fault ride-through and grid-code behaviour defined by regional standards. Instead of embedding every regulation detail into the hardware, the controller board provides measurement and actuation hooks so that firmware can implement anti-islanding detection, low- and high-voltage ride-through and coordinated trips with external protection.

Typical grid codes, such as EN 50549 or IEEE 1547, define operating windows for voltage and frequency, reactive-power support rules, and requirements for detection and response to abnormal conditions. The controller board’s task is to expose accurate measurements and deterministic control paths so that different firmware profiles and grid-code options can be supported without redesigning the hardware.

Measurement hooks for anti-islanding and ride-through

Grid-code features begin with measurement. The controller needs reliable access to grid voltages, currents and derived quantities such as frequency, ROCOF and power, as well as DC-link parameters. These inputs feed anti-islanding detection, voltage and frequency protection and ride-through decision logic.

• Three-phase voltage measurements supply instantaneous and RMS values to PLLs, over- and under-voltage protection and passive anti-islanding algorithms.
• Frequency and ROCOF estimates, typically derived from PLL outputs, allow fast detection of severe disturbances and islanding conditions.
• Current and power (P, Q, power factor) measurements support active and reactive power control curves required by most grid codes.
• DC-link voltage and related signals define limits for sustained ride-through, controlled power reduction and safe shutdown during LVRT or HVRT events.
• External protection inputs from relays or supervisory devices provide an additional viewpoint on grid and plant conditions.

Control paths for ride-through and anti-islanding behaviour

Once the required measurements are available, the controller board must route them into deterministic control paths. These paths implement grid-code functions such as fault ride-through, LVRT and HVRT response and anti-islanding protection. Most actions can be expressed as changes to power references, reactive-power support and gate blocking or soft shutdown.

• Ride-through logic adjusts active and reactive current references during voltage dips or swells while maintaining synchronisation with the grid.
• Anti-islanding algorithms combine voltage, frequency, ROCOF and power information, and may optionally inject controlled perturbations to test system response.
• Protection logic decides when abnormal conditions are severe enough to command gate block, soft shutdown or disconnection from the grid.
• The same hooks allow future firmware updates to implement new or revised grid-code curves without changes to the measurement or power hardware.

Coordination with external protection and standards

A PV inverter rarely operates alone. Protection relays, breakers and plant controllers also observe the grid and command trips. The PV inverter controller therefore needs interfaces that allow grid-code logic to coordinate with external protection devices rather than acting in isolation.

• Dedicated trip outputs and binary status signals can drive external relays or breakers when internal protection detects a critical condition.
• Inputs from external protection devices allow the inverter to shut down on upstream trips, even if local measurements appear acceptable.
• Configurable thresholds, curves and logic blocks provide flexibility to support different regional standards without changing controller hardware.

Communication and monitoring interfaces

Communication interfaces allow plant controllers, SCADA systems and maintenance tools to access inverter measurements, status and events. A PV inverter controller typically offers RS-485, CAN or Ethernet connections so that local HMIs, DER peers and substation gateways can monitor performance and coordinate operation across the site.

Interface selection depends on distance, bandwidth and integration level. RS-485 and Modbus are often used for robust local buses, CAN or CAN FD for coordinated DER devices, and Ethernet for higher-bandwidth links to gateways and SCADA. The controller board exposes these physical and logical interfaces while leaving protocol profiles flexible so that future system architectures remain supported.

Interface options for PV inverter communication

Each interface technology serves a different range and integration layer. Many designs use more than one interface so that local service tools, peer devices and plant controllers can all connect to the same inverter fleet.

• RS-485 with Modbus RTU is commonly used for panel-level monitoring, local HMIs and short-distance links to concentrators or small controllers.
• CAN or CAN FD suits networks of DER devices, such as inverters, battery converters and protection units, especially in cabinets and compact plants.
• Ethernet connections support Modbus TCP, vendor-specific protocols and integration with gateways and SCADA, with options for time synchronisation when required.

Data points and monitoring functions

Monitoring interfaces expose a data model that maps internal signals to external registers or objects. This model typically includes real-time measurements, operating status, events and selected configuration parameters that operators and SCADA systems need to observe and control the inverter.

• Real-time data such as DC and AC power, three-phase voltages and currents, power factor and energy counters.
• Status flags including operating mode, connection status, limit modes and grid-code profile selection.
• Fault and event codes with timestamps and counters for alarms, trips and communication errors.
• Selected configuration parameters such as output power limits, reactive-power settings and communication addresses.

SCADA integration and security hooks

When connecting PV inverters to SCADA or plant controllers, communication design must consider update rates, network loading, protocol conversion and cybersecurity. The controller board provides the necessary physical ports and security hooks so that gateways can perform higher-level protocol translation and fleet management.

• SCADA systems typically poll or subscribe to power and status data at intervals from tens of milliseconds to a few seconds, depending on plant requirements.
• A substation or SCADA gateway aggregates data from multiple inverters and DER devices and translates local protocols into IEC, DNP or utility-facing interfaces.
• Security features such as secure boot and optional cryptographic accelerators support authenticated firmware and encrypted communication when combined with a dedicated cybersecurity module.

Design checklist & IC mapping for a PV inverter controller

This section turns the previous chapters into a practical design checklist and a functional IC mapping. The checklist groups key tasks by sensing, control, gate drive, protection and communication so that a PV inverter controller board can be reviewed before layout and lab testing. The IC mapping then links each function block to typical IC roles and example part numbers that are widely used in grid-tied solar inverters.

Design checklist for a PV inverter controller board

Sensing & AFE (current, voltage and DC-link)

• Confirm that phase currents, DC-link current and critical voltages use appropriate isolated measurement devices (ΣΔ modulators, isolated amplifiers or suitable CT/Hall sensors) with the required working voltage and CMTI.
• Confirm that measurement bandwidth and effective resolution support FOC, power-quality monitoring and protection algorithms, with sufficient margin for future firmware upgrades.
• Confirm that sampling points for phase currents and phase voltages can be aligned to PWM and PLL timing, either by hardware triggers or synchronous ΣΔ clocks, so that control loops see consistent phase angles.
• Confirm that DC-link voltage sensing covers the maximum bus voltage with headroom for over-voltage events, and that it feeds both protection thresholds and LVRT/HVRT decision logic.
• If leakage or ground currents must be monitored, confirm that additional sensors and ADC/ΣΔ channels are reserved and that signal conditioning is compatible with the rest of the AFE.

Control platform (MCU / DSP / digital power SoC)

• Confirm that the controller provides enough high-resolution PWM channels for the main three-phase bridge, any auxiliary bridges and dead-time control.
• Confirm that ADCs or ΣΔ interfaces have sufficient channels, sampling rate and trigger options to acquire all current, voltage and temperature channels in sync with the control loops.
• Confirm that CPU/DSP compute resources can execute FOC, PLL, grid synchronisation, harmonic mitigation and grid-code logic at the target switching frequency with headroom for diagnostics and communication.
• Confirm that the controller exposes the required communication interfaces (such as CAN, RS-485 or Ethernet) and clock resources for plant integration and optional time synchronisation.
• If safety or cybersecurity requirements apply, confirm that secure boot, watchdog and error-logging features are available or that the controller can interface cleanly with external security devices.

Gate drive & isolation

• Confirm that gate drivers provide sufficient peak source and sink current, appropriate gate voltage levels and CMTI for the chosen IGBT or SiC MOSFET modules.
• Confirm that propagation delays and channel-to-channel matching meet dead-time and symmetry requirements for the selected bridge or multilevel topology.
• Confirm that DESAT detection, UVLO, Miller clamp and soft shutdown mechanisms are present and correctly interfaced to over-current and short-circuit protection logic.
• Confirm that isolation ratings, creepage and clearance distances satisfy applicable safety standards for the DC-link voltage and installation category.
• For separated control and power boards, confirm that PWM or digital isolator outputs, bias supplies and connectors support the required distances and assembly practices.

Protection & ride-through behaviour

• Confirm that all grid-code relevant quantities (voltage, frequency, ROCOF, active and reactive power, DC-link voltage) have defined measurement paths and safe operating ranges.
• Confirm that fast protection paths exist from measurement or protection inputs to gate block or soft shutdown outputs, with clear signal naming and test procedures.
• Confirm that the controller can coordinate trips and blocking with external relays, breakers or protection IEDs using dedicated I/O or communication links.
• Confirm that events and faults are stored with timestamps and sufficient detail to support compliance tests, certification and long-term fleet diagnostics.
• For target regions with specific grid codes, confirm that measurement resolution, interfaces and memory are adequate to implement the required curves and operating modes in firmware.

Communication & monitoring

• Confirm that at least one main communication interface (RS-485, CAN or Ethernet) is present and that connectors, isolation and EMC measures suit the cabling environment.
• Confirm that the data model covers real-time power, three-phase voltages and currents, energy counters, operating states and fault codes with clear mapping to protocol objects or registers.
• Confirm that communication interfaces include surge, ESD and common-mode protection appropriate for plant wiring lengths and lightning exposure.
• Confirm that bandwidth and update rates are sufficient for aggregating data from multiple inverters into SCADA or gateway systems without overloading the network.
• If secure communication is required, confirm that secure boot, cryptographic accelerators or external security elements can be integrated into the communication stack.

IC mapping by function block

The table below maps each functional block of a PV inverter controller to typical IC roles, key selection parameters and example part numbers. Example devices are provided as reference points rather than a complete or prescriptive list. More extensive coverage of isolation, sensing and cybersecurity devices is reserved for dedicated pages.

*Example part numbers are provided for orientation only. Detailed isolation, sensing and cybersecurity device families are covered in dedicated pages such as “HV Isolation & Sensing” and “Grid Cybersecurity Module”.

FAQs about PV inverter controller design

This FAQ collects common long-tail questions that appear when turning a PV inverter power concept into a working grid-tied controller board. Each answer links back to the relevant section so that details on sensing, control loops, PLL, gate drive, protection, communication and IC selection can be reviewed in context.