1.Overview
The ENR-RXQ/LXQ type 6-35KV is a nonlinear resistor harmonic elimination damper(harmonic eliminator)designed for the neutral point of voltage transformers.It is installed between the neutral point and ground of the primary winding of 6-35KV voltage transformers(VT or PT).This product features a new modified design with exposed resistors that require no insulating sleeve protection,presenting a cylindrical-shaped harmonic eliminator.While its appearance differs from previous models,its electrical performance remains identical.
2.Functional Applications
Two related issues need to be addressed regarding potential transformers in 6-35KV neutral ineffectively grounded power grids:
1.The overvoltage caused by ferroresonance in potential transformers often leads to internal insulation breakdown and external insulation discharge,frequently resulting in widespread power outages due to delayed or escalating accident handling.
2.Arcing ground faults in the power grid frequently burn out potential transformers.The use of a harmonic eliminator can effectively address these issues:eliminating or damping ferroresonance overvoltage caused by the nonlinear excitation characteristics of potential transformers,which destabilizes system phase voltages;effectively suppressing overcurrent through transformer windings during intermittent arcing ground faults to prevent burnout;limiting inrush current generated in the primary winding circuit when a single-phase ground fault is cleared,which could damage the transformer or blow its fuse;and providing prolonged protection to the transformer against damage after a single-phase ground fault occurs in the system.
3.Operating Environment for ENR-RXQ/LXQ Type 6-35kV Harmonic Eliminator
1.Suitable for indoor and outdoor installation near the potential transformer.Although the harmonic eliminator is rainproof,it should not be directly exposed to sunlight or rain.
2.Ambient temperature range:-40℃to+60℃.
3.The frequency of the AC power system is 50Hz or 60Hz;
4.Areas with seismic intensity below level 8.
IV.Main Electrical Performance
Main performance parameters of ENR-RXQ/LXQ type 6-35KV harmonic eliminator(Table 1)
|
Model |
DC Characteristics KV/mA |
Nonlinear Coefficient a |
Thermal Capacity 250mA/10min |
||
|
ENR-RXQ/LXQ Type 6～10KV |
Universal type |
1.45～1.65/15 |
0.40～0.45 |
pass through |
|
|
Weak insulation type |
1.38～1.45/15 |
0.40～0.45 |
Pass |
||
|
Plateau type |
1.48～1.52/15 |
0.40～0.45 |
Pass |
||
|
Ultra-small |
1.45～1.65/15 |
0.40～0.45 |
Pass |
||
|
ENR-RXQ/LXQ type 35KV |
General purpose |
A |
4.0～4.2/42 |
0.40～0.45 |
Pass |
|
B |
≥2.80～2.85/50 |
0.30～0.40 |
Pass |
||
|
Weak insulation type |
2.60～2.70/50 |
0.35～0.45 |
Pass |
||
|
Plateau type |
1.90～2.10/15 |
0.35～0.45 |
Through |
||
The parameters in the table are typical product specifications of our factory.If customers have different requirements,we can produce according to their needs.
5.Installation of ENR-RXQ/LXQ Type 6-35kV Harmonic Eliminator
1.Installation Method:
The RXQ/LXQ type harmonic eliminator has a compact size and can be installed either vertically or horizontally.It can be directly fixed to the bolts on the voltage transformer body(Note:The fixing bolts of JDZJ-6～10 type voltage transformers are not grounded.The grounding terminal of the harmonic eliminator needs to be connected to the grounding bolt).Alternatively,it can be mounted on a bracket near the voltage transformer.
2.Wiring Diagram:
2.1 When using three single-phase voltage transformers(PT):
Before connecting the harmonic eliminator,the high-voltage winding tails(X,Y,Z)of the three single-phase voltage transformers are either directly grounded or connected in parallel to form a neutral point(0)for grounding.When installing the harmonic eliminator,the directly grounded high-voltage winding tails or(0)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).
2.2 When using a three-phase five-column potential transformer(PT):
Before installing the harmonic eliminator,the neutral point"0"of the three-phase five-column voltage transformer is 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).
2.3 Main installation dimensions of the harmonic eliminator:
Figure 1 Outline drawing of ENR-RXQ/LXQ -6-10 type
Figure 2 Outline and Installation Drawing of ENR-RXQ/LXQ-35KV
VI.No further notice will be given in case of version changes.
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