Why do we use temporary power supply for short circuit test of self-excited generator?

The short-circuit test of a self-excited generator is one of the important tests for evaluating the performance and safety of the generator. When conducting a short-circuit test, a temporary power supply is usually required. This article will discuss in detail the reasons for using a temporary power supply in the short-circuit test of a self-excited generator, as well as the application and advantages of a temporary power supply in a short-circuit test.

1. Overview of short-circuit test of self-excited generator

1.1 Introduction to Self-Shunted Generator

The self-shunt generator is a generator that uses its own magnetic field energy for excitation. It has the advantages of simple structure, stable operation, and convenient maintenance, and is widely used in industry, agriculture, transportation and other fields.

1.2 Purpose of short circuit test

Short-circuit test is an important means to evaluate the performance and safety of generators. By simulating the operation of the generator under short-circuit conditions, the short-circuit current, short-circuit capacity, short-circuit time and other parameters of the generator can be detected, thereby evaluating the short-circuit tolerance and stability of the generator.

1.3 Classification of short circuit tests

Short circuit tests can be divided into two categories: one is external short circuit test, that is, short circuit is performed outside the generator; the other is internal short circuit test, that is, short circuit is performed inside the generator. This article mainly discusses external short circuit test.

2. Reasons for using temporary power supply

2.1 Protecting the Generator

When a short-circuit test is performed, the short-circuit current of the generator will increase sharply, which may cause damage to the internal components of the generator. Using a temporary power supply can effectively protect the generator and avoid damage caused by a short-circuit test.

2.2 Simulating actual operating conditions

In actual operation, the generator may encounter a variety of different load conditions. Using a temporary power supply for short-circuit testing can simulate the operation of the generator under different load conditions, so as to more accurately evaluate the performance of the generator.

2.3 Improving test efficiency

Using temporary power supply for short circuit test can reduce test preparation time and improve test efficiency. At the same time, temporary power supply can be adjusted according to test needs, making the test more flexible.

2.4 Reduce test costs

Using a temporary power supply for short-circuit testing can avoid large-scale modifications to the generator and reduce testing costs.

3. Types and selection of temporary power supply

3.1 Types of temporary power supply

Temporary power sources mainly include the following types:

1. Battery: Battery is a common temporary power source with advantages such as large capacity and stable output.

2. Diesel generator: Diesel generator has the advantages of quick start and stable output, and is suitable for short-circuit tests that require higher power.

3. AC voltage stabilizer: AC voltage stabilizer can provide stable AC power supply and is suitable for short-circuit tests that require precise control of test conditions.

4. DC regulator: DC regulator can provide a stable DC power supply, which is suitable for short-circuit tests that require precise control of test conditions.

3.2 Principles for selecting temporary power supply

When choosing a temporary power source, there are several aspects to consider:

1. Power requirement: Select a suitable temporary power supply based on the power requirement of the short circuit test.

2. Stability: Select a temporary power supply with stable output to ensure the accuracy of the test.

3. Flexibility: Choose a temporary power source that can be adjusted according to test needs to improve test efficiency.

4. Cost: Under the premise of meeting the test requirements, choose a temporary power supply with lower cost.

4. Application of temporary power supply in short circuit test

4.1 Preparation before short circuit test

Before conducting a short-circuit test, the generator needs to be inspected and prepared, including:

1. Check the insulation performance of the generator to ensure that the generator is in good insulation condition.

2. Check the generator's protective device to ensure it is functioning properly.

3. According to the test requirements, select a suitable temporary power supply and install and debug it.

4.2 Implementation of short circuit test

In the short circuit test, the following steps need to be followed:

1. Start the temporary power supply to provide stable power to the generator.

2. Gradually increase the load on the generator until the load level required for the short-circuit test is reached.

3. Observe the operation of the generator and record parameters such as short-circuit current and short-circuit capacity.

4. During the short-circuit test, closely monitor the temperature, vibration and other indicators of the generator to ensure the safety of the generator.

5. After the short-circuit test is completed, gradually reduce the load on the generator until it shuts down.

4.3 Treatment after short circuit test

After the short circuit test is completed, the following processing is required:

1. Perform a thorough inspection of the generator to ensure that there is no damage to the generator.

2. The test data is analyzed to evaluate the short-circuit withstand capability and stability of the generator.

3. According to the test results, make necessary adjustments and optimizations to the generator.

5. Advantages of temporary power supply

5.1 Protecting the Generator

Using a temporary power supply can effectively protect the generator from damage caused by short-circuit testing.

5.2 Improving test efficiency

Using a temporary power supply can reduce test preparation time and improve test efficiency.

5.3 Reduce test costs

Using temporary power sources can avoid large-scale modifications to generators and reduce test costs.

5.4 Flexibility

The temporary power supply can be adjusted according to the test needs, making the test more flexible.

VI. Conclusion

The short-circuit test of the self-excited generator is an important means to evaluate the performance and safety of the generator. Using a temporary power supply for short-circuit testing can effectively protect the generator, improve test efficiency, reduce test costs, and increase test flexibility.