6 to 35KV Nonlinear Resistance Harmonic Reduction DampersDetailed product description：

1、 Product Introduction:
The TXQ (3) type 6-35kV voltage transformer neutral point nonlinear resistance harmonic damper (referred to as harmonic damper) is a nonlinear resistance harmonic damping device installed between the neutral point of the primary winding Y of the 6-35kV voltage transformer (hereinafter referred to as transformer or PT) and the ground. The product model of the harmonic eliminator - TXQ represents a harmonic eliminator designed according to traditional appearance; TXQ3 refers to a cylindrical harmonic eliminator designed for the third modification, with exposed resistor surfaces and no need for insulation jacket protection. The only difference between the two is their appearance, but their electrical performance is completely the same.
The DC electrical characteristics of TXQ (3) type 6-35kV harmonic eliminator are similar to traditional LXQ and RXQ type harmonic eliminators, but the structural design has been greatly improved from the perspective of increasing the thermal capacity of the harmonic eliminator. The harmonic eliminator uses SiC with excellent electrical performance and ultrafine particles as the substrate; Pressed into high-density, round cake shaped bodies by a large tonnage press; Under the restored atmosphere; Made by high-temperature sintering at thousands of degrees. The exposed surface structure of the resistor has been specially treated to withstand sunlight and rain, and can be directly used indoors and outdoors. It is popular among users due to its small size, light weight, fast heat dissipation, high strength, and easy installation.
2、 Application and Function
There are two related problems to be solved for voltage transformers in 6-35KV neutral point non effectively grounded power grids:
The overvoltage generated by the ferromagnetic resonance of the voltage transformer often causes insulation breakdown inside the equipment and discharge of the external insulation, and often leads to large-scale power outages due to delayed accident handling or the expansion of the accident.
2. The arc grounding in the power grid frequently burns out the voltage transformer.
The use of harmonic eliminators can effectively solve the above problems: eliminating or damping the ferromagnetic resonance overvoltage caused by the nonlinear excitation characteristics of voltage variation, which can lead to unstable phase voltage in the system; Can effectively suppress the overcurrent flowing through the voltage transformer winding during intermittent arc grounding, and prevent the burnout of the voltage transformer; Limit the inrush current generated in the primary circuit of the voltage transformer when the single-phase grounding disappears, which can damage the voltage transformer or cause the voltage transformer fuse to melt; When a single-phase grounding occurs in the system, it can protect the voltage transformer from damage for a long time.

3、 Main electrical performance:
Main performance parameters of TXQ (3) type 6-35KV harmonic eliminator (Table 1)

model			DC characteristic KV/mA	Nonlinear coefficient α	Heat capacity 250mA/10min
TXQ (3) type 6-10KV	Electrified type		1.45～1.65/15	0.40～0.45	through
	Weak insulation type		1.38～1.45/15	0.40～0.45	through
	Plateau type		1.48～1.52/15	0.40～0.45	through
	Ultra small size		1.45～1.65/15	0.40～0.45	through
TXQ (3) type 35KV	Universal	A	4.0～4.2/42	0.40～0.45	through
		B	≥2.80～2.85/50	0.30～0.40	through
	Weak insulation type		2.60～2.70/50	0.35～0.45	through
	Plateau type		1.90～2.10/15	0.35～0.45	through

The parameters in the table are typical product parameters. If the user has different requirements, production can be carried out according to the user's requirements.
4、 TXQ (3) type 6-35kV harmonic eliminator operating environment
1. Outdoor, installed near the transformer, although the harmonic eliminator has a rainproof function, it should not be directly exposed to sunlight and rain;
2. The ambient temperature ranges from -40 ℃ to+60 ℃;
3. The frequency of the AC power system is 50HZ or 60HZ;
4. Areas with seismic intensity below 8 degrees.
5、 Installation of TXQ (3) type 6-35KV harmonic eliminator
1. Installation method: TXQ (3) type harmonic eliminator has a small volume and can be installed vertically or horizontally;
It can be directly fixed on the screw of the pressure transformer body (note that the fixing bolts of JDZJ-6-10 pressure transformers are not grounded). The grounding terminal of the harmonic eliminator needs to be connected to the grounding bolt. Also fixed on the bracket near the pressure change.

2. Wiring diagram (see Figure 1)

(1) When there are three single-phase voltage transformers (PT):
Before connecting the harmonic eliminator, the tails (X • Y • Z) of the three single-phase high-voltage windings are directly grounded or connected in parallel to the neutral point (0) for grounding.
When connecting the harmonic eliminator, the high-voltage winding tail or (0) directly grounded must be disconnected from the ground. The harmonic eliminator is connected between the neutral point (0) and the ground (the neutral point is no longer directly grounded).

(2) When the three-phase five column voltage transformer (PT) is used:
Before connecting the harmonic eliminator, the neutral point "0" of the three-phase five column voltage transformer should be directly grounded. When connecting the harmonic eliminator, the neutral point (0) must be disconnected from the ground, and the harmonic eliminator should be connected between the neutral point (0) and the ground (the neutral point is no longer directly grounded).
3. Main installation dimensions of harmonic eliminator:
(TXQ3 type, see Figure 2)

4. Parameter testing of TXQ (3) type harmonic eliminator
On site measurement can use a 1000V shaker to measure the insulation resistance of the harmonic eliminator, which is generally about 0.5M Ω, and can be installed If it is necessary to measure the volt ampere characteristics and nonlinear coefficient α of the harmonic eliminator, the following method can be used for measurement.
(1) Wiring diagram for measuring DC volt ampere characteristics: (see Figure 4)

(2) Testing the Nonlinear Coefficient α Method:
When the DC characteristic of the harmonic eliminator is set to 15mA, the voltages U1 and U2 at both ends of the harmonic eliminator are measured at 50mA and 50mA DC, respectively; When the DC characteristics of the harmonic eliminator are 42mA or 50mA, the rigid nonlinear coefficients α of the voltages U1 and U2 at both ends are measured for DC 100mA and 10mA, respectively
Voltage when U1=I1 is 50 (100) mA; Voltage when U2=I2 is 5 (10) mA;
lg
When I1=50 (100) mA, I2=5 (10) mA
lg=lg10=1
=lg

The mouth coefficient of the harmonic generator should comply with the values specified in Table 1.
(3) Thermal capacity spot check test: (see Figure 5)

Require the harmonic eliminator to withstand a 250mA power frequency current for 10 minutes without any burning or bursting phenomenon; When the harmonic eliminator is still in a high temperature condition, immediately spray water on the harmonic eliminator, and the harmonic eliminator body should be kept intact; After the harmonic eliminator is cooled and completely dried, its DC voltage change rate and DC nonlinear coefficient α change rate are both not greater than 10%.