Power electronic equipments are more and more widely used in industry and commerce, such as frequency conversion timing devices, rectifiers, UPS, DC power, welding machines, computers, televisions, energy saving lamps, photocopiers, etc. These nonlinear loads will bring convenience to people's production and life. At the same time, they will generate large amounts of harmonics and infuse into the power grid, resulting in the distortion of current and voltage waveforms, the deterioration of power quality, and the damage to power grid and other devices in the power grid.

APF active filter device

The harm of harmonics to power supply equipment:
Increasing the loss of power transformers and generators, resulting in overheating；
Cable overheating, insulation aging；
The dielectric loss of the power capacitor increases and overheats
The midline current increases, overheats
The harm of harmonics to electric equipment:
Sensitive load is disturbed, PLC error, and crash
Abnormal action of protection device, switch fault tripping;
The servo motor produces pulsation, the AC motor produces vibration and the noise increases.
The transmission lines transmit electromagnetic interference, digital transmission failure and communication interruption.
Lighting equipment and display flicker
The harm of harmonics to the power grid:
The quality of the power grid is deteriorating, the distortion of the waveform increases, and the frequency changes;
Excessive consumption of reactive power and current effective values in the power grid;

The burden of the power grid is aggravated and the available capacity falls.

Benefits of dynamic reactive power and harmonic control equipment

①By improving the power factor, the total electric current in the line and the capacity of the electrical components in the power supply system, such as transformers, electrical equipment, conductors and so on, are reduced. Therefore, not only the investment cost is reduced, but also the loss of electric energy is reduced.
②The good work due to the guarantee of numerical value, thus reducing the voltage loss in the power supply system, can make the load voltage more stable and improve the quality of the electric energy.
③It can increase the margin of the system and excavate the potential of power supply equipment. If the power factor of the system is low, then when the capacity of the existing equipment is constant, the power factor can be increased and the load capacity can be increased after installing the capacitor.
　　For example, when the power factor of the 1000KVA transformer is increased from 0.8 to 0.98:
　　Before compensation: 1000 x 0.8=800KW
　　After compensation: 1000 x 0.98=980KW
　　The same 1000KVA transformer, when the power factor changes, it can bear 180KW load more.
Reduce the electricity expense of the user; the electric fee discount through the reduction of the loss of the above elements and the increase of the power factor.

TSF type harmonic control equipment

Product overview
CX-APF series active power filter device is designed and developed by Chang Xiang electric and North China Electric Power University, which is fully consistent with China's GB standard. It can perfectly filter the harmonic in the power grid and is not affected by the operation structure of the power grid.
CX-APF adopts precise modular design. The capacity of single module is 50A, 75A and 100A which are optional. According to the harmonic current content in the field, multiple modules can be expanded and the largest expansion is to 600A. And the cabinet can expand the capacity further, the flexible configuration, the small size and the portable installation provides great convenience for the user’s design and installation
Working principle
Through the current transformer load current detection, and through the internal DSP calculations, CX active power filter extract the harmonic components in the current, and then through the PWM signal sent to the internal IGBT, the control inverter generates a harmonic current grid equal to the load harmonic current but in the opposite direction injected into the power to achieve the purpose of filtering.

Technical characteristics
Excellent filtering effect
1.The harmonic control efficiency is up to 95%, the harmonic control range is 2-50 times, and the single harmonic filtering depth can reach 100%.
2.The industry's subversive control mode, the switching frequency is as high as 20KHZ, and the filter loss is reduced to the minimum, which does not affect the system impedance. The output waveform is accurate, and it will not affect other devices.
3.The capacity of the input voltage fluctuation and distortion is stronger.
4.One machine is multi-functional; a filter can simultaneously control harmonics, reactive power and unbalanced three-phase.
5.Friendly Chinese operating interface.
6.Various protection functions: over current, overvoltage, undervoltage, overtemperature, detection circuit fault and many other protection functions.
7.The advanced modular structure, small volume, high volume ratio, the single cabinet can be installed at most 6 modules and can be embedded in the third square cabinet.
Product model description

TZ-APF/3L-400V-50A/B

Annotation:
1. Series of code: TZ series
2. Connection mode: 3L indicates three phase three wire system, 4L indicates three phase four wire system
3. Rated voltage: 400V/690V
4. Rated current: 50~3600A
5.Installation form: A is wall hanging type, B is superposition type, C is cabinet type.

Dynamic compensator for thyristor:
The dynamic filter and reactive power compensation device is flexible, effective and fast response. It can not only filter the harmonic and compensate reactive power dynamically, but also solve the power quality problems such as three-phase imbalance, flicker and voltage fluctuation. It is an economic type of power grid management equipment.
Model selection description
CX-TSF/3L-400V-200KVAR

Annotation:
1. Series of code: CX seriesCX系列
2. Connection mode: 3L indicates three phase three wire system, 4L indicates three phase four wire system
3. Rated voltage: 400V/690V
4. Installation capacity: 200~3500KVAR