How to select SVG static reactive power compensators in situations with more starters

In industrial settings such as metallurgy, mining, ports, and large-scale machinery manufacturing, the centralized starting of asynchronous motors is a typical scenario. When multiple high-power motors start simultaneously or sequentially, a significant surge of inductive reactive current is generated, causing a sudden drop in grid voltage and a sharp deterioration of power factor. In such "highly motorized" situations, selecting and applying SVG static reactive power generators is a cutting-edge solution to the problem. However, the selection of such generators is of crucial importance and must follow specific principles.

Ⅰ. How to configure SVG for "multiple starters" scenarios?

It cannot be simply selected based on the steady-state reactive power demand; instead, it must be designed based on the transient impact.

1. Capacity calculation: Select based on the maximum instantaneous reactive power demand.

This is the most crucial and error-prone point. The capacity (in kvar) of SVG must meet the maximum transient reactive power demand generated by all the motors that may be started simultaneously, rather than only considering the total reactive power deficit during steady-state operation.

2. Response speed: Must be at the millisecond level

All SVGs claim to have fast response times, but it must be clearly stated in the technical protocol: the total response time ≤ 5ms. This is the core advantage of SVG compared to traditional compensation devices, ensuring that it can keep up with the rising slope of the motor's starting current.

3. Function Configuration: Emphasizing Specific Functions

Voltage stabilization mode priority: Select an SVG that supports "voltage stabilization mode" or "constant voltage control". In this mode, the SVG takes stabilizing the voltage at the busbar as its primary goal. It automatically generates or absorbs reactive power to counteract voltage fluctuations, which provides the best suppression effect on voltage drops during motor startup.

II. Summary and Recommendations for Model Selection

To select SVG for applications with more starters, the following steps can be followed:

1. Research and statistics: Collect and record all motor power, starting current, starting methods (direct start/soft start/frequency conversion), as well as the maximum simultaneous starting power and the number of units under the most adverse conditions.
2. Capacity Calculation: Using the aforementioned formula or empirical rules, determine the total capacity of the required SVG, and appropriately increase the margin by one level.
3. Function Confirmation: Clearly define the required functions with the supplier, especially the "voltage stabilization mode" and the rapid response capability.
4. Positioning Design: Collaborate with the design institute or electrical engineers to determine the optimal installation location (busbar/fuse line) for the SVG.
5. Environmental Adaptation: Based on the actual environmental temperature and dust conditions, determine the protection and cooling schemes for the cabinet.
6. Brand Selection: Choose mature brands that have a large number of successful application cases in the industrial field. Their product stability and control algorithms have been verified through practical use.