Static Var Generator

DELTA Static Var Generator (SVG) is used for dynamic reactive power compensation, Unbalanced load compensation,voltage stability improvement and Harmonics Mitigation. It can provide compensation in grid supply. Apart from the grid supply network, it can support dynamic loads fed from the Generator. SVG has a good steady state performance with ultra-fast response and superior control characteristics. It can be operated dynamically to compensate to fast varying capacitive, Inductive, Unbalanced loads and Current Harmonics in the system.

The Static Var Generator (SVG) is an IGBT based INVERTER to compensate reactive power as well as selective harmonics created by the load and unbalance in the system. Single unit ratings of SVG are available in 100 kVAr, 250 kVAr, 300 kVAr & 1000 kVAr.

The inverter cabinet is rated for IP54 (Electronics section) / IP43 (Inductor cooling section) and houses all the components like IGBT stack, cooling system, AC circuit breakers, LC harmonic filters and other main controllers and communication interfaces.

Basic Operation

Delta’s SVG is connected in parallel with grid, and uses current transformers (CT) on the grid side to calculate harmonic current along with reactive current required by the load, and then generates a compensating current with the same amplitude thereby allowing the Grid to provide only active current required by the load. The SVG eliminates the harmonics from grid current and mitigates harmonic voltage caused by harmonic currents. The SVG system also improves power factor (PF) and correct load imbalances in the power system.

Reactive Compensation

SVG performs reactive power compensation with a very fast reaction time. This feature makes them effective even with fast fluctuating loads. It is capable of correcting both leading and lagging power factor situations. The reactive compensation by SVG is accurate and smooth without any risk of voltage transients or resonance.

Unbalance Compensation

Simulation below shows a two phase load, this is the most severe case of unbalance in an industry. The current unbalance is ~100%. The two phase current is decomposed into the Positive Sequence and the Negative Sequence current by the DSP micro controller.

SVG then supplies the negative sequence current component so that the corrected waveform only has the Positive Sequence current
left. The positive sequence current is perfectly balanced in the three phases. Thus, regardless of the type of load, the source only
sees a balanced load leading to optimum capacity utilization.

Harmonic Compensation

SVG performs harmonic compensation with a very fast reaction time. This feature makes them effective even with fast fluctuating loads. SVG can be programmed to correct a combination of harmonic orders without any change in the hardware at all. Moreover, the filter is connected in shunt therefore it is very easy to connect or disconnect from the load. Additionally, the filter is compatible with future load expansions unlike traditional filters which need to be replaced if the load increases in the future.

The SVG can be configured as to clients need with respect to their load demands. A combination of reactive, unbalance and harmonics can be easily achieved as well as priority of compensation can be taken into consideration depending on the load.