Skip to main content

Archive

Show more

Do you know why generator has unbalanced load

 

Why is the three-phase load of diesel generator unbalanced? Today Starlight Power answers for you.


Here are some reasons:

1.One phase of the generator and its circuit occurs phase loss, or one phase of its circuit breaker is in poor contact.

2.A power transmission sequence is in incomplete operation.

3.Single phase of the system is overloaded(if there is a single-phase load with large capacity).

4.The failure of stator ammeter and circuit of electric energy metering device also contribute to the indicative asymmetry of three phase ammeter.

 

Hazards of the unbalanced three-phase load of diesel generator.

1.It will undermine the operational output of the equipment. The design for capacity of the generator is fixed according to the three-phase load, so that the equipment takes the largest phase in it as the limit in consequence of the three-phase unbalance, and lead to the inefficient operation of the equipment.

2.When electricity goes through the neutral line, wastage of the low voltage line increases.

3.It will lead to the asymmetry of three-phase voltage and the displacement for electric potential of neutral point.

4.Excessive neutral current will rise the temperature of power transformer when it is in service, and will burn it out at worst.

5.It is able to undermine the output power of the generator, and rise the winding temperature.

6.It will make the voltage of some phases high and others low.

7.When the neutral line is overcurrent, the alien line might be burn out.

 

How to solve the problem of unbalanced three-phase load?

When the generator overruns under the three-phase imbalance load, you should immediately reduce the load of the generator set to make the unbalanced current lower than the allowed value and report to the system control. After the three-phase current becomes balanced, you can increase the load of the generator set according to the dispatching order. The current difference of the three phases must be lower than the 20% of rated current, and current of any phase must be of below rated value. The negative-sequence current goes through the generator must be less than 12% of the rated current.


 Yuchai genset


To better learn about the diesel generator and make a right decision in purchasing, the three-phase loads and single-phase load will be introduced here:

1.Three-phase load

Three-phase loads are defined as providing power source for the operation of power-driven equipment with three phases. The three-phase loads can fall into the balance of three-phase loads and the imbalance of three-phase loads.

The differences are as follow: the balance of three-phase loads sees similar values of current for the three phases; the imbalance of three-phase loads sees great different values of current for the three phases, and the phase with overcurrent is prone to cause a fire.

 

2.Single-phase load

Single-phase load is defined as the one or more impedances that are set in the two lines of the three-phase power source. It can also be deemed as a peculiar asymmetric three-phase loads. Electric locomotive is a classic example of it. In order to ensure the basic balance of three-phase loads, all the single-phase load will be evenly set in the three phases.

 

In a word, the single-phase means using a phase, which is commonly known as live wire, and a null line to provide power source for the operation of the electric appliance.

 

Therefore, when make a decision on the purchase for a diesel generator, whether the load of the generator is three-phase or single-phase should be confirmed. In doing so, imbalance in the load of a generator in service can be avoided, so as to make certain of the safe and stable operation of the generator set.

 

Being established in 1974, Jiangsu Starlight Electricity Equipments Co., Ltd. is a manufacturer for diesel generator sets. We are committed to the production of high-quality diesel generator sets, providing products including Cummins, Perkins, Volvo, Deutz, Yuchai, SDEC, Weichai, Ricardo, MTU and the likes, with the power range from 20 KW to 3000 KW. For more information, please contact us by e-mail sales@dieselgeneratorech.com or telephone +86 13481024441.

Comments

Popular posts from this blog

New Yuchai engine YC6K600-D30 power for diesel generator 50Hz

Silent Cummins 640kw Diesel Generating Sets

Technical data of 800KVA AC diesel generator set The DG Set is skid mounted, directly coupled with Cummins water cooled engine with built in shock absorber for anti vibration. The alternator is Stamford brand with brushless and self excited, with control panel and protection system complete set. Prime power: 640KW/800KVA Standby power:704KW/880KVA Rated voltage: 230/400V Rated current: 1152A Speed/frequency:1500rpm/50Hz ( or 1800rpm/60Hz) Power factory:0.8lag Size: open type genset: 4.2 x1.82x2.25m, silent genset: 6.5 x2.6 x2.78m Net wight: open type genset: 7800kg,   silent genset : 12000kg Technical Data of Diesel Engine Diesel engine brand/model: Chongqing Cummins/ KTA38-G2B( full new) Prime/standby power: 790KW/920KW 4 Stroke Cycle , 60° Vee , 12 Cylinder, Turbocharged &Aftercooled, 1500rpm, 50Hz, bore/stroke: 159/159mm. The Cummins diesel engine is equipped with electronic type governor, over speed shutdown devices to protect against runaway when electronic governor or con...

Guides to Clean VOLVO Diesel Generator Cooling System

VOLVO Engine Cooling System Volvo engine's internal cooling system makes sure the engine works at the right temperature. It is a closed system that must always be filled with a mixture of concentrated coolant and water in order to protect the engine against internal corrosion, cavitation and bursting due to freezing. Coolant of a suitable chemical composition must be used all year round. This also applies in areas where there is never any risk of freezing, to provide the engine of  diesel generator set   with full corrosion protection. The use of anti-corrosion agents alone is not permitted in Volvo Penta engines. Never use water alone as a substitute for coolant. The corrosion protection additives become less effective over time, which means that the coolant must be changed at regular intervals; refer to Maintenance Schedule. The cooling system must be flushed whenever the coolant is changed; Volvo Penta coolants have been prepared to work best ...