Active Power Filter(APF)

Active power filter (APF) is a new type of power harmonic control equipment made of modern power electronics technology and digital signal processing technology based on high-speed DSP devices. It consists of two main parts: command current operation circuit and compensation current generation circuit. The command current operation circuit monitors the current in the line in real time, converts the analog current signal into digital signal, sends the signal to the high-speed digital signal processor (DSP) for processing, separates the harmonics from the fundamental wave, and sends the drive pulse to the compensation current generating circuit in the form of pulse width modulation (PWM) signal, drives the IGBT or IPM power module. A compensating current with equal amplitude and opposite polarity of harmonic current is generated and injected into the power grid to compensate or cancel harmonic current and actively eliminate power harmonics.

Type explanation 

Product dimensions

380V 150kvar module

380V 150A/100A module

380V 75A/50A module

380V 35A module

660V 100A/50A module

● Modular design, any module failure will not affect the normal work of other modules, greatly improve the reliability of the whole equipment; It can realize smooth expansion of multiple units running directly in parallel. When multiple devices are added, the master/slave control mode is adopted. When multiple modules are connected in parallel, all modules can share a set of current transformer;

● It can filter the odd harmonic current below 2~50 times at the same time, and can set the harmonic subsegment that needs 13 kinds of filtering according to the need. When the load current distortion rate is greater than 20%, the filtration rate is not less than 85%; When the load current distortion rate is less than 20%, the filtration rate is not less than 75%

● The fifth-generation IGBT of international famous brand can automatically adjust the output according to the harmonic current of the load and dynamically filter;

● The fifth-generation IGBT of international famous brand can automatically adjust the output according to the harmonic  current of the load and dynamically filter;

● Layered design, dust and rain will not adhere to the circuit board, adapt to the use of harsh conditions;

● Using the sliding window iterative DFT detection algorithm, the calculation speed is fast, the instantaneous response time is less than 0.1ms, and the compensation full response time is less than 20ms.

● The output filter is connected to the power grid with the LCL structure, and its own high-frequency carrier will not feed back to the power grid, and there is no interference to other devices in the distribution system.

● With a complete protection function, including overvoltage, overcurrent, overheating, short circuit and other complete protection functions, while with the system self-diagnosis function;

● Adopt reliable current limiting control link, when the system to be compensated current is greater than the rated capacity of the device, the device can automatically limit the current at 100% capacity output, maintain normal operation, will not appear overload and burn and other failures;

● To save space for users, the maximum power of the 600mm wide cabinet is 400A, and the power of the 800mm wide cabinet can reach 800A.