Key technology sharing of energy saving and consumption reduction of transformer

With the rapid development of urban social economy, the contradiction between energy supply and demand has become increasingly prominent. For power supply and distribution systems, it is particularly important to promote energy-saving and technical measures and equipment. Transformer is the core energy distribution dispatching equipment in power supply and distribution system. Its energy-saving economic dispatching operation is the top priority of power system energy-saving research. Reasonable measures to reduce transformer energy consumption are the key to power supply and distribution system.

First, the key technology of energy saving and consumption reduction of transformer

1.1 Adopt new materials

In the transformer manufacturing, the use of new materials instead of aluminum alloy or steel materials can enhance the corrosion resistance of the transformer and reduce the resistance, thereby achieving the purpose of energy saving. There are currently two main types of new materials that are popular. The first type is an oxygen-free copper material, which can effectively reduce the internal resistance of the coil of the distribution transformer and achieve the purpose of energy saving. The oxygen-free copper material has the characteristics of simple processing technology, convenient material selection and low cost, and is also beneficial for enhancing the resistance of the distribution transformer to short circuit. The second is the use of amorphous alloy materials as magnet materials for distribution transformers. The iron core made of amorphous alloy material can effectively reduce the electromagnetic loss, thereby achieving the purpose of improving the economics of the distribution transformer.

1.2 Adding an automatic voltage regulator

The loss of the transformer is closely related to the voltage of the distribution network. By installing the corresponding compensation capacitor on the load tap position of the transformer, it is possible to optimize and adjust the operating voltage of the distribution network. The automatic voltage regulator is a device that uses a three-phase coupling transformer to automatically adjust the ratio according to the actual input voltage value of the distribution transformer to ensure the output voltage is stable, so that the input voltage value is automatically adjusted within 3% of the normal value, and the internal use is utilized. The corresponding controller controls the voltage of the entire system in real time to achieve the maximum energy saving.

1.3 Economic operation mode of distribution transformer

The energy consumption of the distribution transformer is not only related to the manufacturing materials and processing technology of the distributor, but also has a great relationship with the operation mode of the distribution transformer. Therefore, optimizing the operation mode of the distribution transformer is the key to energy saving and consumption reduction of the distribution transformer. At present, the operation mode of the traditional distribution transformer is still adopted in China. The operation mode of the traditional transformer is not reasonable enough, which results in high energy consumption of the transformer and cannot meet the economic requirements. . In the actual power distribution system, no power consumption compensation can be adopted. The specific measure is to install the parallel transformer reactive power compensation component in the power distribution system, which can provide the reactive power consumed by the inductive load. Commonly used methods include, first, grouping compensation of distribution transformers, paralleling no-power components at low voltage. The second is to adopt advanced technical means to keep the three operating conditions of the transformer in line with the long-term balanced working conditions. In addition, an important technical means to reduce the running loss of the distribution transformer is to make the distribution transformer basically in balance by adjusting the balance of the three-phase load. In the actual distribution transformer, when the three-phase load is unbalanced, the negative sequence voltage will be caused, and the system voltage will fluctuate, thus affecting the energy consumption of the power distribution system. When the three-phase distribution transformer is unbalanced, it not only increases its own energy consumption, but also increases the loss of the line. Therefore, it is necessary to balance the three-phase power.

Second, the analysis of measures for energy-saving operation of transformers

2.1 Preferred energy-saving and economical distribution transformer

In the process of selecting the design and distribution of distribution transformers, it is preferable to control energy-saving and economical products with low loss rate on the basis of technical feasibility. For example, the S11 and S13 energy-saving and economical distribution transformers are more mature in engineering. Compared with the S9 series transformers, the control loss is reduced by about 30%, the control current is reduced by about 40%, and the overload capability is strong. The comprehensive energy saving effect is more obvious. The distribution transformer of S13 series has relatively small line loss, and is more suitable for power distribution systems with large fluctuations in operating load, which can meet the engineering field with large load fluctuation of modern power distribution system.

2.2 Using multiple distribution transformers to jointly operate energy-saving scheduling

As the scale and capacity of distribution network systems continue to expand, the system load capacity changes are also frequent, and the losses in various operating modes are also very different. The optimal operating conditions and scheduling methods should also change with it. In order to achieve the purpose of energy saving.

During the operation of the distribution transformer, its own no-load loss and load loss together form the active loss of the transformer operation, which will change nonlinearly with the load change. Among them: the no-load loss is a specific coefficient, basically not It will change with the change of the load ratio of the transformer; and the load loss is a variation of the load fluctuation, which is proportional to the square of the load current of the transformer. In the joint operation of multiple transformers, there is always a lowest point is the lowest point of the load factor, which is the lowest point of the integrated power economic load factor of the joint operation of the distribution transformer. According to the actual situation of the power distribution system, the optimal load operation condition point and economic load area of the transformer should be reasonably calculated, and multiple distribution transformers should be used for joint economic dispatch operation, and different loads should be calculated according to the operating characteristics of the load from small to large. The best transformer operation in the region is matched with the number of units and the operation mode. The optimal economic operation area for the joint operation of multiple distribution transformers is determined according to the comprehensive power load relationship, so as to avoid the occurrence of “large horse-drawn cars” and other non-economic operating conditions. Effectively improve the safety, reliability and energy saving economy of distribution transformers.

2.3 Adjusting the unbalanced load ratio of the distribution transformers to achieve energy-saving economic operation

Due to the large proportion of single-phase power load in distribution transformers and their power distribution systems, and with the widespread use of various energy-saving electrical equipment, energy-saving lamps, etc., distribution transformers, especially public distribution transformers The three-phase load unbalance is large, and the corresponding loss is large. This indicates that the load loss caused by the three-phase unbalance is very large, which is a key point in the research of energy-saving economic operation of the transformer. Through reasonable phase-to-phase load optimization and adjustment, the load imbalance between the three phases is reduced, and the three-phase load of the distribution transformer is almost close to the equilibrium relationship, so that a better phase-to-phase balance relationship can be obtained, and the active loss during the operation of the distribution transformer can be reduced. Reactive power consumption improves the efficiency of power distribution scheduling conversion.

2.4 Perform appropriate reactive power compensation

From the operating conditions of the distribution transformer and the load curve between the load and the load, it can be known that the reactive load of the distribution transformer is mainly concentrated in the light load or no-load operating conditions, and the reactive power is generated at this time, and the reactive capacity consumed is It is about 10% to 15% of the rated capacity of the distribution transformer. Therefore, centralized reactive power compensation measures can be taken. By reasonably selecting reactive power compensation devices such as SVC, SVG, TSC, etc., the mortgage reactive compensation capacitor is connected to the bus side of the distribution transformer through the load switch, and the system operates at light load or no load. In working condition, the capacitor can be cut reasonably to perform reactive power compensation in real time, improve the power factor of the 10kV power distribution system, effectively reduce the running loss of the distribution transformer, and at the same time achieve the energy-saving economic effect of improving the end voltage and improving the voltage quality.

Reprinted from the network