Industrial Grade 30a 50a 75a 100a 150a High Protection Active Power Filter Apf

Short Description:

More and more loads are non-linear, introducing harmonics into the power grid and thus significantly impairing the power quality. NK active harmonic filter ahf is an ideal product effectively reduces the unwanted harmonics. Non-linear loads, by contrast with linear loads, have become increasingly common: frequency converters in drive systems, the large numbers of switch-mode power supplies used in IT and communications equipment, and also more and more in household electronics.

Even lighting technology employs mainly non-linear power supplies. Non-linear loads becomes more and more in industrial plants, office buildings, data centers or even private households. Industrial grade active power filter apf based on our company many years experience, is a very reliable product. The user can set the parameters so that the active harmonic filter ahf can simultaneously filter out harmonics, dynamically compensate reactive power, compensate for three phase unbalance, and compensate for voltage drop, etc.

Product Detail

Product Tags



Active power filter apf is a new type of electronic device for dynamic filtering of harmonic wave and reactive power compensation. It can conduct real-time filtering and compensation to harmonic wave (both size and frequency are changed) and dynamic reactive power, and is used to overcome disadvantages of traditional harmonic suppression and reactive compensation methods of traditional filters,thus realizing systematic harmonic filtering function and reactive power compensation function. In addition, it is widely applied into power,metallurgy. petroleum, port, chemical and industrial and mining enterprises.

Active harmonic filter adopts advanced modular design. An active filter system consists of one or several AHF modules and an optional touch screen HMI. Each AHF module is an independent harmonic filtering system, and users can change the configuration of the harmonic filtering system by adding or removing AHF modules.

The AHF is available in three mounting modes: rack mounted, wall mounted, cabinet mounted.

1. Modular design, any module failure will not affect the normal operation of other modules, greatly improving the reliability of the whole equipment; can achieve smooth expansion of multiple direct parallel operation.The master-slave control mode is used when multiple units are expanded; when multiple modules are connected in parallel, all modules can share a set of current transformers.
2. The odd-order harmonic currents of 2 to 50 times or less can be filtered out at the same time, and the harmonics of the 13 types of filtering can be set as needed.When the load current distortion rate is >20%, not less than 85%; when the load current distortion rate is <20%, not less than 75%; reactive power compensation can make the power factor reach 1; the three-phase current unbalance can be corrected to complete balance;
3. Use the fifth generation IGBT of imported international well-known brand, it can automatically adjust the output according to the harmonic current of the load, and dynamically filter;
4. Use the American Xilinx military-grade FPGA control chip, which has fast running speed and high reliability;
5. With a layered design, dust and rain will not adhere to the circuit board, adapting to the use under harsh conditions;
6. Filtering, compensating reactive power, compensating for three-phase unbalance can be single-selected or multi-selected, and can set the priority of functions;
7. Use the iterative DFT detection algorithm of sliding window , the calculation speed is fast, the transient response time is less than 0.1ms, and the full response time of device compensation is less than 20ms;

8. The output filtering uses the LCL structure to connect to the grid, and its own high-frequency carrier does not feed back to the grid, and there is no interference to other devices in the power distribution system;
9.  Complete protection functions, including over-voltage, over-current, over-heat, short-circuit and other complete protection functions, as well as system self-diagnosis function;
10.  It has a soft start control loop to avoid excessive inrush current at the moment of starting, and limits the current between the rated ranges;
11. Use the reliable current limiting control link. When the current to be compensated in the system is greater than the rated capacity of the device, the device can automatically limit the output to 100% capacity, maintain normal operation, and no faults such as overload burning;
12. The main circuit uses a three-level topology, and the output waveform has high quality and low switching loss;
13. The wall mounted module comes with a 4.3 touch screen for parameter setting, parameter viewing, status viewing, event viewing and more.It can also be centrally monitored by high-definition 7-inch touch screen, which is easy to operate. The screen displays the system and device operating parameters in real time, and has a fault alarm function.
14. Save space for users, the maximum power of 600mm wide cabinet is 300A/200kvar, and the power of 800mm wide cabinet can reach 750A/500kvar.

APF pinciple

After the circuit breaker is closed, in order to prevent the instantaneous impact of the grid on the DC bus capacitors during power-on, the APF/SVG firstly charges the DC bus capacitor through the soft-start resistor.When the bus voltage Udc reaches a predetermined value, the main contactor is closed.As a energy storage device, the DC capacitor supplies energy to the external output of the compensation current through the IGBT inverter and the internal reactor.The APF/SVG sends the current signal through the external CT to the signal conditioning circuit and then to the controller.The controller decomposes the sampling current, extracts each harmonic current, reactive current, and three-phase unbalanced current, and compares the collected current component to be compensated with the compensation current that has been sent by APF/SVG to obtain a difference. The real-time compensation signal is output to the driving circuit, and the IGBT converter is triggered to inject the compensation current into the power grid to realize closed-loop control and complete the compensation function.

active harmonic filter

The active harmonic filter operates on a 3-level neutral point clamped(NPC) topology. As shown in the above, the traditional 2-level topology circuit structure consists of 6 IGBTs( 2 IGBT power devices on each phase pin and current path ), and in the 3-level topology, there are 12 IGBTs( in each phase 4 IGBT power devices on pins and current paths ).

The 3-level topology circuit can generate three voltage levels at the output, including DC bus positive voltage, zero voltage and DC bus negative voltage. Two-level topology circuit can only output positive and negative voltages. At the same time, the three-level topology circuit also ensures higher quality and better harmonic output voltage, thereby reducing output filter requirements and associated costs.


Network voltage(V) 400
Network voltage range -20%--+20%
Network frequency(Hz)


Harmonic filtering capability It is better than the standard JB/T11067-2011 low voltage Active Power Filter.
CT mounting method

Closed or open loop(Open loop is recommended in parallel operation)

CT mounting position

Grid side/load side

Response time


Connection method


Overload capacity

110%Continuous operation, 120%-1min

Circuit topology

Three-level topology

Switching frequency(khz)


Protective function

Parallel between modules 

Redundancy Over 20 kinds of protections such as over-voltage, under-voltage, overheating, over-current, short circuit, etc.

No screen/4.3/7 inch screen(optional)

Line current rating(A) 35、50、75、100、150、200 100
Harmonic range

2nd to 50th order odd times

Communication port


Communication method

         RS485,Modbus protocol                       

PC software  Yes, all parameters can be set by the host computer
Error alarm  Yes, up to 500 alarm messages can be recorded
Monitoring  Support independent monitoring of each module / centralized monitoring of the whole machine
Noise level


Mounting type            Wall-mounted, rack-mounted, cabinet

Derating usage>1500m


Operating temperature: -45℃--55℃,  derating usage above 55℃

Storage temperature: -45℃--70℃


5%--95%RH, non-condensing

Protection class



EN 62477-1(2012), EN 61439-1(2011)


EN/IEC 61000-6-4, Class A



Product display

AFP board

The active power filter adopts the hardware structure of FPGA, and the components are of high quality. Thermal simulation technology is used for thermal design of the system, and multi-layer PCB circuit board design ensures reliable isolation of high and low pressure, which provides guarantee for system safety.


active harmonic filter cabinet

Active power filter can be widely used in power system, electroplating, water treatment equipment, petrochemical enterprises, large shopping malls and office buildings, precision electronics enterprises, airport/port power supply system, medical institutions and so on. According to the different application objects, the application of APF active filter will play a role in ensuring the reliability of power supply, reducing interference, improving product quality, extending equipment life, reducing equipment damage and so on.

Active harmonic filter mostly used as below:

1) Data center and UPS system;

2) New energy power generation, e.g. PV and wind power;

3) Precision equipment manufacturing, e.g. single crystal silicon, semiconductoe;

4) Industrial production machine;

5) Electrical welding system;

6) Plastic industrial machinery, e.g. extrusion machines, injection molding machines, molding machines;

7) Office building and shopping mall;

Customer service

1. ODM/OEM service is offered.

2. Quick order confirmation.

3. Fast delivery time.

4. Convenient payment term.

At present, the company is vigorously expanding overseas markets and global layout. We are committed to becoming one of the top ten export enterprises in China’s electrical automatic product, serving the world with high-quality products and achieving a win-win situation with more customers.


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