Medium-voltage SVG cabinets cover 1 Mvar to 10 Mvar per HISVG-X skid at 6 kV and 10 kV, with air-cooled as the default and water-cooled required above 4 Mvar at 10 kV [S1].
Low-voltage SVG/AHF modules from Shanghai-based suppliers such as YT Electric, Hiconics, and Sineng use voltage-source converter (chain-inverter) topologies with IGBT stacks, and are sold alongside hybrid VAR compensators and medium-voltage STATCOM skids [S2][S3][S4].
Price-vs-Mvar Curve: Where the kV Class Bends the Curve
Static VAR generator cost scales primarily with reactive-power rating, with the 6 kV HISVG-X range covering 1–8 Mvar per cabinet and the 10 kV range covering 1–6 Mvar per cabinet in published sizing tables [S1]. Above 4 Mvar at 10 kV, vendors switch from air-cooled to air-cooled or water-cooled skids because the IGBT chain losses exceed what finned heatsinks can dump at the rated ambient [S1]. The chain-inverter (H-bridge cascaded) topology is the standard arrangement for medium-voltage SVG, with each power cabinet linking to a starter cabinet, control cabinet, and a connected reactor or connected transformer that interfaces to the grid bus [S3]. Optical fibre between controller and converter chain is the typical comms path because of the high dv/dt on the IGBT module terminals [S3].
Reactive-current generation is governed by the susceptance principle: the difference between inverter AC voltage and grid AC voltage across the connected reactance produces a continuously variable leading or lagging current, and split-phase control is achievable in delta connection [S3]. Per the technical reference, the Hiconics SVG brochure lists a capacitive-to-inductive compensation range of -1 to +1 in per-unit terms, meaning the same module can source or sink reactive current without capacitor-bank reconfiguration [S4].
Cost Drivers Engineers Can Actually Negotiate
Four variables dominate a Static VAR Generator quote, and the published sizing data lets each be sized before RFQ. First, Mvar rating: the 6 kV HISVG-X line tops out at 8 Mvar per cabinet and the 10 kV line at 6 Mvar per cabinet, so multi-cabinet paralleling is required for substation-scale compensation (typical 30 Mvar to 100 Mvar+ STATCOM blocks) [S1]. Second, cooling: air-cooled suffices to 4 Mvar at 10 kV, while water-cooled is the engineered option above that point, and the closed-loop deionised-water skid adds plumping, heat exchangers, and a redundancy pump that materially shifts the bill of materials [S1]. Third, IGBT chain count: the chain-converter architecture stacks H-bridge cells in series, so every extra voltage class step (e.g. 6 kV to 10 kV) usually adds cells and DC-link capacitors per phase, raising both power-module cost and control-complexity cost [S3]. Fourth, harmonic-filtering integration: when the SVG also has to function as an active harmonic filter, the controller must run harmonic-current loops on top of the reactive-current loop, which can be met within the same IGBT stack (per the HISVG description, "when the inverter outputs a specific order of harmonic voltage, it can output the corresponding order of harmonic current") [S3].
YT Electric's published positioning matches this architecture: SVG technical advantages are fast response, good low-voltage characteristics, superior harmonic characteristics, high compensation accuracy, and improved safety performance, with their active power filter and SVG module production having exceeded 10,000 units in 2021 [S2]. That volume figure, while a 2021 data point, suggests Chinese low-voltage SVG/AHF pricing is anchored on a mature local supply chain. For broader grid-quality economics, the static var generator reference page lays out the operating envelope engineers should confirm against their bus short-circuit ratio before sizing.
Side-by-Side: LV SVG, MV SVG, and STATCOM on Decision Criteria
Three architectures compete in the reactive-power market and the right choice depends on bus voltage, response time, and harmonic duty. Low-voltage SVG modules (typically 400 V / 480 V class, 50 kvar to 200 kvar per module) are the cheapest entry point and are paralleled for larger LV compensation; Shanghai YT's product line combines the active power filter and SVG into a single module platform, with hybrid VAR compensators bridging the gap to MV [S2]. Medium-voltage SVG (the 6 kV / 10 kV HISVG-X family) is the workhorse for plant-internal compensation at arc-furnace, rolling-mill, mining, petrochemical, coalmine, and port loads, with explicit use cases covering power-factor control, bus-voltage flicker suppression, unbalanced-load compensation, and load harmonic-current filtering [S1]. Medium-voltage STATCOM (often quoted for transmission-scale 30 Mvar to 200 Mvar blocks) overlaps with cascaded MV SVG but is typically sold as a turnkey containerised solution rather than a switchgear-integrated cabinet [S2]. Sineng's SPC product line, by contrast, is a power-quality control platform covering SVG, AHF, and energy storage interfacing, targeting solar and utility-scale applications [S4].
For the decision matrix, the criteria most procurement engineers ask about are: (1) bus voltage — LV SVG below 690 V, MV SVG at 6 kV / 10 kV, STATCOM at 10 kV+; (2) harmonic performance — AHF and SVG both offer active harmonic filtering, but AHF-only modules are cheaper if reactive-power compensation is not needed; (3) response time — voltage-source converter SVGs respond in the sub-cycle to few-cycle range, far faster than the thyristor-switched capacitor (TSC) branch of an SVC; and (4) footprint — MV SVG cabinet footprints from the HISVG-X datasheet run 1900 mm to 2750 mm long by 2200 mm high by 1100 mm deep per cabinet, and multi-cabinet paralleling scales linearly with Mvar [S1]. The Chinese-language technical primer on SVG/STATCOM topology confirms the underlying IGBT-based voltage-sourced-converter (VSC) architecture and the use of a self-commutated bridge circuit with DC-link capacitor and grid-side reactor, which is the same building block used across all three product classes [S5].
What SVG Pricing Excludes: Installation, Commissioning, and TCO
Published cabinet prices rarely include the items that make up 20–40% of a project budget. For an MV SVG, the connected reactor or connected transformer is typically quoted separately (the HISVG bill of materials lists "connected reactor (or connected transformer)" as a distinct line item alongside the starter cabinet, control cabinet, and power cabinet) [S3]. Water-cooled configurations add a heat-exchanger skid, deionised-water circulation pump, and a redundancy pump that the air-cooled option does not need [S1]. Beyond hardware, the dominant hidden costs are: site acceptance test (FAT/SAT) time, protection-relay coordination with the existing switchgear (the SVG must coexist with any existing capacitor banks, and back-to-back switching of TSC branches can produce transients the SVG controller must handle), and the bus short-circuit ratio study that determines whether the SVG can stably operate without a harmonic resonance with the supply network.
From a total-cost-of-ownership perspective, the European power-quality cost data cited on YT's site — "Europe loses 150 billion euros a year because of power quality problems (Voltage Sag, Short Outage, Harmonic Interference, Long Outage, The Transient Impact)" — provides the macro-economic justification, and the supplier notes that "to avoid these losses, only 5% investment is required" of that exposure class [S2]. For industrial buyers who have already justified an SVC or STATCOM investment, the next data point to track is the per-Mvar hardware cost trajectory of Chinese MV SVG cabinets, which has trended down as IGBT module prices (particularly 1700 V and 3300 V classes from Infineon, Mitsubishi, and CRRC-affiliated foundries) have fallen. Related cost breakdowns on switchgear-adjacent equipment such as the MCC price & cost guide cover the parallel motor-control-center procurement that usually ships in the same substation build.
Standards, Sourcing, and the Documents to Demand at RFQ
SVG equipment is not governed by a single dedicated product standard the way switchgear is, but several adjacent standards shape the RFQ. Power quality and harmonic compliance typically reference IEEE 519 harmonic-distortion limits at the point of common coupling, and EMC/IEEE compliance for the control electronics is mandatory for grid-tied equipment. For utility-scale STATCOM, grid-code compliance (voltage ride-through, reactive-current injection during faults) varies by region and must be specified per project. For Chinese suppliers shipping to European customers, CE/EMC conformity and IEC 61800 (adjustable-speed electrical power drive systems) overlap applies because the IGBT converter chain is, fundamentally, a grid-tied VSC. The 1998-era 500 kVAR static VAR generator paper from NARI (Nanjing Automation Research Institute) published in Electricity journal remains a useful historical reference for early Chinese SVG engineering and confirms that the 500 kVAR class was a published benchmark at that time [S7].
At RFQ, the document set to demand is: (1) the Mvar-versus-kV-class sizing table for the specific product family, with the cabinet outline drawing and water-cooled skid GA; (2) the IGBT module part number and the chain-cell count per phase, which determines spares strategy; (3) the controller-to-converter comms architecture (optical fibre is the norm for MV); (4) the harmonic-compensation order list, since some MV SVG products compensate only specific harmonic orders (e.g. 5th, 7th, 11th, 13th) and additional passive filtering is needed for the rest [S3]; and (5) the cooling-water specification (conductivity, flow rate, inlet temperature) for water-cooled configurations. For the underlying topology, the function generator reference covers the control-side PWM signalling used to drive the IGBT chain, while adjacent procurement topics such as VFD-driven motor packages are covered in the VFD-duty motor cost breakdown and downstream metering selection in the electricity meter cost breakdown — both of which typically ship alongside an SVG project on the same switchboard line-up. Track the next nodes: Hiconics 2026 H2 product catalogue release (mid-tier 10 kV SVG with integrated AHF) and any 1500 V DC-link SVG product targeting solar-plus-storage plant applications per the Sineng SPC roadmap.
Spec-level background on the components involved: linear guide.