heightPassive compressionReactive power compensationComplete set of equipment

1、 Application scenarios
1high-powersemiconductorRectification deviceIncluding situations where there are many DC motors and variable frequency speed regulating motors
Electrolytic aluminum, intermediate frequency furnace, rolling millDuring the process of turning off and on semiconductor devices, characteristic harmonics related to their wiring methods are generated. The harmonic currents flowing into the system can affect the normal operation of transformers and motors, causing them to overload or even burn out.
2Electric locomotiveSingle phase electrical load or three-phase severely unbalanced load
At present, most of the electrified railway locomotives in operation in various countries use AC 25-35KV power supply, with two-phase power supply from the front strain power station. This inevitably causes three-phase load asymmetry, thereby injecting harmonic currents and sequence currents into the power system together. Generally, filters with the same capacity are installed on the two power supply arms of the traction transformer.
3Negative of devices with ferromagnetic propertiesload
In some power supply and consumption systems,Transformer, iron core reactorWhen it operates in a saturated state, due to the nonlinearity of the magnetization curve, a certain number of harmonics will be generated, with the third harmonic being the main one. When there are parallel compensation capacitors in the system, a suitable ratio between the capacitance reactance of the capacitors and the system inductance reactance will cause severe amplification of the third harmonic.
IIDevice features
High voltage complete sets of equipment can be divided into two forms according to installation methods:

1. Cabinet type

The entire device is installed inside the high-voltage cabinet, but if hollow filter reactors are used, they should not be installed inside the cabinet. If they are affected by the site and must be installed inside the cabinet, magnetic shielding measures must be taken.
Its characteristics are: miniaturization of the device, convenient transportation and reduced footprint, compact structure of the complete set of devices, reasonable layout, fully considering the simplicity and intuitiveness of installation and operation maintenance.

2. Framework style

The commonly used installation form for filtering equipment includes:
a) Incoming and protective cabinets: containing circuit breakers, isolating switches, and current transformers, etc;
b) Relay protection screen: realizing functions such as protection, automatic switching, measurement, and communication;
c) Primary components: including filtering capacitors, filtering reactors, discharge coils, lightning arresters, and spray type fuses, etc;
d) Steel frame and fence, etc.
Good series performance: The main equipment, steel structure, and spare parts of the complete set of equipment are standardized and appropriately divided into different capacity levels. The selection of control equipment such as circuit breakers, protective devices, and automatic switching, as well as the protection methods for individual capacitors, fully respects the opinions and suggestions of users, and the manufacturer supplies complete sets according to the contract requirements.
Strong flexibility: It can meet the different requirements of urban power grids, rural power grids, and heavy industrial loads for power quality, and can simultaneously compensate for reactive power, increase system voltage, and improve voltage distortion rate.
Strong adaptability: China has a vast territory with significant differences in climate conditions between the north and south, cold and tropical regions, and high-altitude areas. The different designs of the complete equipment fully meet its reliable operation under different climate conditions.
Complete equipment according toThe cutting methods can be divided into the following types:
1) Manual switching
The entire device can be composed of several sets or one set of filters, which can be manually operated by the operator.
Manual switching filtering devices are generally suitable for substations or factory distribution systems with personnel on duty.
2) Automatic switching
The entire device can be composed of several sets or one set of filters, which are automatically switched in sequence by the controller. The control parameters can be selected from harmonic generation or voltage reactive power.
Automatic switching filtering devices are generally suitable for unmanned substations or factory distribution systems, or for situations where system harmonics (reactive power) change frequently.
IIIOrdering Notice
The basic principle of designing a filtering device is to achieve the specified indicators of bus voltage distortion rate and harmonic current value with minimal investment under a determined system and harmonic source, and to meet the requirements of reactive power compensation, ensuring the safe, reliable, and economical operation of the device. Therefore, before designing the filtering device, users are required to provide the following information:
System main wiring and equipment (main transformer, cable, etc.) parameters
Operating parameters of the power grid (voltage, frequency variation, voltage imbalance, etc.)
Harmonic impedance characteristics of the system
Load characteristics (nature, size, harmonic impedance, etc. of the load)
Characteristics of harmonic sources (harmonic order, amplitude, and fluctuation)
The background harmonic level of the system
Reactive power compensation requirements and required harmonic indicators
If there is an existing parallel compensation capacitor, its installation location, capacity, voltage, wiring method, and reactance rate should be provided