What this page solves

This page helps decide when a static capacitor or reactor bank is no longer enough and a dedicated SVG / STATCOM is required. It focuses on engineering decision points rather than control theory derivations, so that reactive power and voltage support can be planned with clear technical and commercial trade-offs in mind.

Typical triggers include millisecond-level response requirements, tight limits on harmonics and flicker, and interconnection rules that demand dynamic voltage support or low-voltage ride-through. Under these conditions, step-changed capacitor banks and mechanical contactors struggle to follow the grid, and semiconductor-based SVG / STATCOM solutions become the natural next step.

The goal is to provide one place where the SVG control, power stage and protection chain are organized into a coherent design path. Other pages in this cluster cover metering, power-quality analysis and DER controllers in more detail. Here the focus is specifically on when and how to deploy an SVG / STATCOM as a programmable reactive power resource on the grid.

Where SVG / STATCOM fits in the grid

An SVG / STATCOM behaves as a programmable reactive power source tied directly to a grid bus. It can be placed on transmission or distribution feeders, at renewable plant points of interconnection, or on industrial medium-voltage buses where fast voltage support and power-factor control are critical.

In a substation, the cabinet often connects near the transformer or main bus to influence a whole feeder group. In a wind or solar plant, it supports the collector bus and point of common coupling. In an industrial site, it stabilizes the internal distribution bus that feeds large drives, furnaces and cranes, helping the facility meet contractual limits on voltage flicker and power-factor penalties.

The diagram below focuses on placement and controlled quantities rather than power quality reporting. Analytics, event recording and detailed harmonic metrics are handled on the dedicated Power Quality Analyzer page in this smart grid cluster.

Key electrical & control requirements

An SVG / STATCOM design starts from grid-side electrical constraints. Voltage level, target MVar range and available short-circuit current determine insulation ratings, converter topology and the stress that gate drivers, isolation and measurement components must withstand. These values also influence how many modules or bridges need to be paralleled to deliver the required reactive power range safely.

Grid codes add further limits on harmonic distortion, flicker and power factor windows, as well as interconnection rules such as low- and high-voltage ride-through. Meeting these constraints requires accurate current and voltage sensing, stable PLL performance and control loops that can react within milliseconds without exciting oscillations or over-stressing the power stage during faults or deep voltage sags.

To achieve these objectives, the current loop bandwidth, outer voltage-loop speed, harmonic compensation range and unbalanced-sequence control must all be dimensioned explicitly. In practice this translates into hard requirements on ADC sampling rate and resolution, digital power SoC MIPS, available hardware accelerators, PWM timer resolution and communication bandwidth to substations, SCADA and plant controllers. The diagram below summarizes how grid limits flow down into control targets and finally into IC requirements.

Power stage & converter topologies

SVG / STATCOM systems typically use two-level voltage-source converters, three-level NPC or ANPC bridges, or modular multilevel converter structures. The chosen topology sets the number of switching devices, the stress on each device and the way that fault current flows through the power path. These factors directly dictate the number of gate driver channels, isolation barriers and auxiliary power rails needed in the design.

Two-level bridges keep the device count relatively low but operate at higher dv/dt and common-mode voltages, so gate drivers, digital isolators and current-sense circuits must tolerate aggressive transients. Three-level NPC and ANPC converters distribute voltage across more devices, improve waveform quality and shrink filters, but require additional driver channels, mid-point voltage monitoring and more complex fault-handling logic.

In higher-power installations, modular multilevel converters introduce large numbers of identical submodules, each with its own switches, capacitors and measurement points. This approach trades per-device stress for system-level complexity and can drive the architecture toward local monitoring ASICs, high-channel-count gate driver solutions, distributed isolated DC/DC power and centralized fault aggregation. The diagram below contrasts the topologies and highlights their impact on driver, isolation and protection IC roles.

Digital power SoC & real-time control

The digital power SoC at the heart of an SVG / STATCOM closes the current and voltage loops, runs dq transformations and harmonic or sequence-compensation algorithms, and keeps the converter synchronized to the grid through PLL functions. It also enforces low-voltage ride-through behavior, manages limiting and derating under faults and coordinates the various protection and monitoring paths around the power stage.

Architecture choices range from fixed-point or floating-point digital power SoCs and DSPs to MCU plus FPGA combinations where high-speed PWM generation, ΣΔ filtering or sequence decomposition are offloaded. Required performance depends on loop bandwidth, harmonic compensation depth, the number of converter bridges or modules and any need to support multi-level or modular multilevel topologies with complex fault handling.

Meeting grid-code and power-quality targets drives hard requirements on PWM units, ADC trigger modes, sampling synchronization and communication interfaces. High resolution PWM, tightly coupled ADC triggers and deterministic interrupt timing are needed to maintain stable loops, while Ethernet, RS-485, CAN or optical links connect the digital power SoC to substations, SCADA gateways, microgrid controllers and cybersecurity modules. The diagram below shows the SoC at the center of measurements, power stages and communications.

Isolated measurement chain

The isolated measurement chain feeds the digital power SoC with accurate information about phase currents, grid and bus voltages, mid-point voltage in three-level converters and DC-link current and voltage. These signals form the basis for current loops, voltage support, sequence control and protection functions, so their bandwidth, delay and stability must align with the control targets defined for the SVG / STATCOM system.

Implementation options include ΣΔ modulators with digital filters, isolated amplifiers and Hall or TMR current sensors with companion AFEs. ΣΔ solutions offer high resolution and robust digital isolation but introduce fixed filter delay that must be compensated in the control loop. Isolated amplifiers provide analog outputs with defined gain and bandwidth, and magnetic sensors reduce insertion loss at high currents while adding their own constraints on linearity and drift.

Across all approaches, common-mode transient immunity, effective bandwidth, phase delay, temperature drift and synchronous sampling across multiple channels are key design variables. These parameters drive the selection of current-sense ΣΔ devices, isolated amplifiers, precision references and multi-channel AFE devices, while broader isolation topics are covered by the dedicated HV isolation and sensing page.

Protection, thermal & reliability

SVG / STATCOM converters face short-circuit, overcurrent, overvoltage, overtemperature, loss-of-synchronism and islanding conditions. A robust design builds several layers of coordinated protection, starting with fast gate-driver desaturation detection, followed by comparator and latch networks, and ending with a digital power SoC fault manager. These layers must react quickly enough to protect power modules while still supporting grid-code requirements for ride-through and availability.

Thermal management is equally important for long-term reliability. Junction and heatsink temperatures are monitored with NTCs, PT100/ PT1000 RTDs or integrated temperature sensors, then processed by dedicated thermal monitor ICs to implement warning, derating and shutdown thresholds. De-rating curves versus ambient temperature, load profile and switching frequency are used to keep power modules within safe cycling limits and to extend lifetime in demanding substation or renewable plant environments.

Typical IC hooks include gate drivers with integrated desaturation and Miller clamp such as UCC21750-Q1 or ADuM4137, high-speed window comparators like TLV7031-Q1 or LMV7235, multi-channel supervisors such as TPS386000 and thermal monitor devices like TMP451-Q1, LTC2997 or MAX6680. These devices create a hardware safety shell around the SVG, while station-wide backup and UPS strategies are handled separately by the Backup / UPS for Substation subsystem.

Communications, grid codes & cybersecurity hooks

An SVG / STATCOM rarely operates in isolation; it is part of a substation or microgrid where SCADA systems, substation IEDs and microgrid controllers coordinate power quality and voltage support. The converter must expose measurements, events and controllable parameters through industrial Ethernet, TSN, IEC 61850, Modbus/TCP or legacy serial links, using deterministic channels for time-critical data while reserving lower priority paths for configuration and diagnostics traffic.

Grid codes drive which quantities are exchanged: reactive and active power, power factor, harmonic and flicker indicators, LVRT and HVRT events, as well as settings for Q, PF or voltage-regulation modes. Time synchronization via PTP or NTP aligns event logs and measurements with protection relays and power quality analyzers. To secure these links, the SVG control platform needs hooks for secure boot, key and certificate storage and encrypted tunnels that are implemented in a dedicated grid cybersecurity module or gateway.

Typical IC hooks include TSN-capable Ethernet PHYs and switches such as DP83TG720, DP83869 or KSZ9477, digital power SoCs or CPUs with integrated crypto accelerators and TRNG blocks, secure elements or HSMs like ATECC608A or TPM 2.0 devices, and robust watchdog and supervisor ICs such as TPS3430 or MAX16055. The detailed VPN, TLS and security-policy implementation is covered by the dedicated Grid Cybersecurity Module page; this section focuses on ensuring that SVG hardware and firmware expose the right interfaces to plug into that architecture.

Design checklist & IC mapping

This checklist and IC mapping section is intended as a quick review tool before committing to an SVG / STATCOM cabinet design. Each item can be ticked off during the concept and schematic phases to ensure that grid targets, power-stage topology, digital control resources, measurement bandwidth, protection layers, thermal design and communications/security hooks are all aligned.

Design checklist before committing to an SVG cabinet

Grid targets & power capability

• ✔ Target grid voltage level, transformer ratio and MVar range are defined, including overload or leading/lagging reactive power capability.
• ✔ Applicable grid codes and power-quality limits are identified (THD, flicker, power-factor window, LVRT/UVRT), with response-time requirements expressed as quantitative ms-level targets.

Topology & power stage

• ✔ Converter topology is selected (two-level, three-level NPC/ANPC, or MMC), and device blocking voltages, module count per phase and switching-frequency range are quantified.
• ✔ Required number of gate-driver channels, isolation voltage ratings and isolated DC/DC rails is derived from the chosen topology and mechanical arrangement.
• ✔ Output filter structure and expected harmonic attenuation are defined so that current and voltage loop bandwidth targets are realistic.

Digital control SoC / DSP capability

• ✔ A suitable digital power SoC / DSP or MCU plus FPGA architecture is chosen, with headroom for dq control, harmonic or sequence compensation, PLL and LVRT logic.
• ✔ ADC sampling rate, number of channels and trigger structure can cover all phase currents, grid and bus voltages, mid-point voltage and DC-link current/voltage with synchronized sampling.
• ✔ PWM / HRPWM resolution, dead-time control and channel count are sufficient for the number of bridges and for the required current-loop bandwidth and THD performance.
• ✔ Control MIPS, FPU or accelerator resources and interrupt latency are checked against worst-case loop timings, including any MMC sub-module balancing or parallel-bridge coordination tasks.

Measurement, protection & thermal management

• ✔ For each key measurement point (phase currents, grid and bus voltages, mid-point voltage, DC-link current and voltage), a technology path is chosen (ΣΔ modulator, isolated amplifier, Hall / TMR sensor plus AFE) with quantified bandwidth and phase delay.
• ✔ Total measurement-chain delay and CMTI capability are budgeted and aligned with loop bandwidth and switching-node dv/dt in the chosen topology.
• ✔ A layered protection concept is in place: gate-driver desaturation and UVLO, fast comparators and latches for hard interlocks, and a digital power SoC fault manager for ride-through, derating and logging.
• ✔ Thermal sensing points (power-module junction estimate, heatsink temperature, cabinet ambient) and thresholds for warning, derating and shutdown are defined, along with fan control and derating curves versus ambient and load profile.

Communications, grid integration & security hooks

• ✔ Upstream systems to be connected (SCADA, substation IEDs, microgrid controller, DR / DER aggregator) are identified, together with their preferred protocols.
• ✔ The communications mix is selected (TSN Ethernet, IEC 61850, Modbus/TCP, RS-485, CAN, fiber), with clear priorities for time-critical control and event data versus configuration and diagnostics.
• ✔ Hooks for secure boot, key and certificate storage, VPN / TLS termination and watchdog supervision are reserved so that the SVG cabinet can be integrated into a grid cybersecurity architecture.

When all points in the checklist are satisfied and consistent with insulation coordination, mechanical layout and thermal design, the SVG cabinet is ready to move into prototype and lab validation with a clear set of technical assumptions.

IC mapping: typical device families for SVG / STATCOM

The following IC families illustrate where digital power SoCs, gate drivers, isolated measurement devices, thermal monitors, communications parts and security components can be sourced. Part numbers are examples and do not form an exhaustive list; procurement and brand-focused pages can refine these options by voltage rating, package, temperature grade and lifecycle.

Digital power SoC / DSP for SVG control

• TI C2000 digital power control — TMS320F28379D, TMS320F28388D, TMS320F280049C: integrated HRPWM, multiple ADC modules and power-control peripherals for three-phase and multi-bridge SVG control.
• Infineon AURIX and XMC — SAK-TC397 系列, XMC4400-F64K512: multi-core safety microcontrollers and motor-control MCUs for high-end SVG and STATCOM platforms.
• MCU + FPGA combinations — STM32H743 or LPC55S69 paired with a small FPGA such as Lattice MachXO3 for designs that offload PWM generation, ΣΔ filtering or MMC sub-module balancing into programmable logic.

Gate drivers & isolated power

• IGBT / SiC gate drivers — TI UCC21750-Q1, UCC21710-Q1, UCC21530A-Q1; Analog Devices ADuM4137, ADuM4135; Infineon 1EDCxx and 2EDxxx families for high-side and low-side isolated gate driving with desaturation and Miller-clamp support.
• Isolated DC/DC for gate drivers — Murata MGJ6 series, RECOM RxxPxxD, or discrete transformer-driver solutions based on TI SN6505A / SN6505B to feed multiple isolated gate-driver channels.

Isolated measurement: ΣΔ, isolated amplifiers and sensors

• ΣΔ modulators for current and voltage — TI AMC1304M25, AMC1305L25, AMC1306M25; Analog Devices AD7403 and AD7401A for isolated shunt current sensing and high-linearity voltage measurement into digital filters.
• Isolated amplifiers — TI AMC1100, AMC1200, AMC3301 families for isolated measurement of phase currents, bus and DC-link voltages with defined gain and bandwidth.
• Magnetic current sensors and AFEs — Hall and TMR sensor modules from LEM or Tamura for high-current paths, combined with shunt current sense amplifiers such as TI INA240 or INA241 when additional shunt-based measurement is required.

Thermal monitoring & protection ICs

• Temperature monitors — TI TMP451-Q1, TMP235 and TMP102; Analog Devices ADT7410; Maxim Integrated MAX6680 and MAX6690 for single- and multi-channel temperature measurement on modules, heatsinks and critical boards.
• Comparators and window detectors — TI TLV7031-Q1, LMV7235; Analog Devices ADCMP600 series for fast overcurrent, overvoltage and window comparisons tied into latch networks.
• Supervisors and watchdogs — TI TPS386000, TPS3430; Maxim MAX16055 to monitor supply rails and the digital power SoC, providing reset and fault outputs into the protection chain.

Communications & time synchronization

• TSN / industrial Ethernet PHY and switches — TI DP83TG720S, DP83869; Microchip KSZ9477 and KSZ9567 families for substation Ethernet and TSN networks with hardware timestamp support.
• Serial transceivers — RS-485 and CAN / CAN FD transceiver families such as TI SN65HVDxxx and TCANxxx devices for auxiliary links to local controllers, HMI panels and sensor boards.

Cybersecurity hooks & secure elements

• Secure elements and HSMs — Microchip ATECC608A; Infineon OPTIGA Trust devices and TPM 2.0 parts such as SLB 9670 for key and certificate storage and secure-boot roots of trust.
• MCUs with hardware crypto — families such as NXP LPC55Sxx and ST STM32H7 or STM32U5 with AES, SHA and TRNG accelerators to offload TLS and VPN processing in cooperation with a grid cybersecurity module.
• Watchdog and supervisor ICs — TPS3430 and MAX16055 ensuring the control platform is reset or forced into a safe state if firmware hangs or a security event disrupts normal operation.

Recommended topics you might also need

• PV Inverter Controller
• Battery PCS for Grid
• Power Quality Analyzer
• Microgrid Controller
• Substation Time Sync (PTP/NTP/GNSS)

FAQs about SVG / STATCOM design

These questions summarise the key design and procurement decisions for an SVG / STATCOM cabinet. Each answer links back to the relevant section of this page so you can jump into more detail when refining requirements, comparing IC families or preparing specifications for design partners and suppliers.