Views: 0 Author: Site Editor Publish Time: 2025-03-14 Origin: Site
In modern industrial power system, the optimization of power quality is very important. Active power Filter (AHF) and static VAR generator (SVG) as two key equipment, each play a unique role. This article will delve into the differences between the two devices to help you better understand and choose the right power solution.
AHF (Active Power Filter)
AHF is mainly used for harmonic control. It detects the harmonic current in the system in real time, and generates the reverse compensation current to offset the harmonics, so as to purify the grid current and reduce the adverse effects of harmonics on the equipment and the grid. For example, in industrial environments with a large number of nonlinear loads (such as frequency converters, uninterruptible power equipment, etc.), AHF can effectively reduce the risk of equipment overheating and failure due to harmonics, and extend the service life of equipment.
SVG (Static reactive Power Generator)
The core function of SVG is reactive power compensation. By injecting reactive power into the grid, it can support and regulate the voltage of the grid, improve the power factor and improve the power quality. In the scenario where the power grid load changes greatly or there is voltage fluctuation, SVG can respond quickly to maintain the stability of the power grid voltage and ensure the normal operation of the power equipment.
AHF
The working principle of AHF is based on current detection and compensation. The external current transformer (CT) monitors the load current in real time, the digital signal processor (DSP) analyzes the current, and uses intelligent fast Fourier transform (FFT) to decompose the load current into active power and reactive power parts, and quickly and accurately calculate the harmonic content. Subsequently, the DSP sends a pulse width modulation (PWM) signal to the internal insulated gate bipolar transistor (IGBT) driver board to control the switching frequency of the IGBT, and finally generates a compensation current opposite to the harmonic current phase on the inverter sensor to achieve harmonic cancellation.
SVG
SVG works similarly to AHF, but focuses on reactive power generation and regulation. When the load generates inductive or capacitive current, SVG detects the phase difference between the current and voltage, and injects the corresponding reactive current into the grid, so that the phase of the transformer side current is basically consistent with the voltage, thus realizing the correction of the fundamental power factor. In addition, SVG also has a certain harmonic control ability, can compensate for a specific number of harmonics.
AHF
Suitable for occasions with high demand for harmonic control, such as:
- Industrial environment: Plants with a large number of nonlinear loads such as frequency converters and uninterruptible power supplies.
- Commercial buildings: office buildings and shopping malls equipped with computer equipment, lighting systems, etc.
- Data centers: Places where power supply quality and equipment stability are highly required.
SVG
It is mainly used in scenarios that require reactive power compensation and voltage regulation, including:
- Industrial plant: large motor, transformer and other equipment more industrial enterprises.
- Wind farm: new energy generation field, used to stabilize grid voltage, improve power quality.
- Other places where reactive power compensation is needed: hospitals, schools, etc.
AHF technical parameters
- Rated capacity: According to the actual demand has a variety of specifications, such as 23A, 15A, 25A, 50A, 75A, 100A, 150A, etc.
- System voltage: covers 220V, 380V, 500V, 690V and other voltage levels.
- Response time: <40ms, can quickly respond to harmonic changes in the system.
- Harmonic compensation frequency: It can compensate from 2 to 50 harmonics, the compensation frequency is optional, and the single compensation range is adjustable.
- Compensation rate: >92%, effectively reduce the impact of harmonics on the power grid.
- Efficiency: >97% to ensure the high efficiency of equipment operation.
SVG technical parameters
- Rated capacity: including 5kvar, 10kvar, 15kvar, 35kvar, 50kvar, 75kvar, 100kvar, 90kvar, 120kvar and other specifications.
- System voltage: also covers 220V, 380V, 500V, 690V and other common voltage levels.
- Response time: <10ms, faster than AHF response, can quickly provide reactive power support.
- Reactive power compensation rate: >95%, efficiently improve the power factor.
- Efficiency: >97%, to ensure the economic operation of the equipment.
When choosing AHF or SVG, consider the following factors:
- Main requirements: If the harmonics problem is prominent in the system, AHF is preferred; If the focus is on reactive power compensation and voltage regulation, SVG is a more appropriate choice.
- Load characteristics: AHF harmonic control function is particularly important for nonlinear loads; For systems dominated by inductive or capacitive loads, SVG's reactive power compensation capabilities will play a greater role.
- Response speed requirements: For scenarios that require very high response speed, such as rapidly changing industrial production lines, the fast response feature of SVG is more advantageous.
- Installation environment and space: Both AHF and SVG have various installation modes, such as wall-mounted and rack-mounted, which must be selected according to the actual installation environment and space conditions.
In short, AHF and SVG play their respective roles in the power system, and reasonable selection and application of these two devices can effectively improve the power quality, ensure the stable operation of electrical equipment, and provide reliable power support for industrial production and daily life.