What is a power busbar ?

    In the power system, the busbar is an important component for collecting, distributing and transmitting electric energy. It is a conductive connection point, usually made of copper or aluminum, which serves to connect generators, transformers, loads and other power equipment. The busbar is connected to other parts of the power system through power switches and protection devices to achieve the distribution and dispatch of electric energy.

1. The role of the busbar

1. Collecting electric energy: The busbar collects the electric energy from multiple generators or transformers together so that it can be transmitted and distributed through one or more lines.

2. Electric energy distribution: The busbar can distribute electric energy to multiple loads to ensure that electricity can be effectively delivered to various parts. It is the core part of the distribution system.

3. Simplify the system structure: Connecting multiple power equipment through the busbar reduces the complex line layout and simplifies the structure and maintenance difficulty of the power system.

4. Power dispatching: The busbar can dispatch power according to the needs of the system, such as switching different lines or loads to achieve flexible distribution of power.

5. Voltage control: The busbar is connected to a transformer or compensation device to maintain the voltage stability of the system, especially when power generation and load fluctuate.

2. Working principle of busbar

The working principle of busbar is to realize the collection and distribution of electric energy by connecting multiple power sources (such as generators or transformers) and loads (such as factories and houses) together. Power equipment is connected to the busbar through circuit breakers and disconnectors to realize the opening, closing and switching operations of the circuit.

The busbar usually works at high voltage, requiring it to have good conductivity and sufficient mechanical strength to withstand large currents. To ensure the reliability of the power system, the busbar is equipped with protection devices (such as circuit breakers, relay protection devices), which can quickly cut off the faulty part in the event of a fault to avoid large-scale power outages.

3. Types of busbar

Based on the structure and application, busbars can be divided into the following types:

1. Single busbar system:

- Structure: The single busbar system consists of a busbar connecting all generators, loads and power equipment.

- Advantages: simple structure, low cost, suitable for small power systems.

- Disadvantages: When a bus fails, the entire system may be out of power, and the reliability is low.

2. Double bus system:

- Structure: It consists of two busbars, each of which can independently connect the generator and the load, usually connected and switched through a bus coupler.

- Advantages: It has higher reliability. When one bus fails, the other bus can continue to supply power. It is suitable for large substations and occasions with high reliability requirements.

- Disadvantages: High cost and complex structure.

3. Bus segmentation system:

- Structure: The bus is divided into multiple parts, and each part is connected by a circuit breaker or bus coupler.

- Advantages: The bus segmentation system can isolate the fault area in the event of a fault, keep the rest of the parts running normally, and improve the reliability of the system.

- Disadvantages: More switchgear is required, which increases the cost and complexity of the system.

4. Ring bus system:

- Structure: The busbars in the ring bus system connect the generator and the load in a ring structure. The current in the system can flow in both directions.

- Advantages: It has better flexibility and redundancy. When a part fails, it can continue to supply power from another direction.

- Disadvantages: The design is relatively complex and the cost is high. It is suitable for ultra-high voltage transmission systems.

5. Breaker-and-a-Half Scheme:

- Structure: It consists of three circuit breakers and two busbars. The load and power generation equipment are connected between the two circuit breakers respectively, and the busbar is divided into two independent lines.

- Advantages: The system provides high redundancy and flexibility. Even in the event of a fault, power can still be supplied through another busbar. It is widely used in large-capacity substations.

- Disadvantages: The design and cost are relatively high, and the operation and maintenance are relatively complex.

    The busbar plays the role of collecting, distributing and dispatching electric energy in the power system. According to the needs and scale of the system, the busbar can have different structures, such as single busbar, double busbar, busbar segmentation, ring busbar and circuit breaker half busbar system. Different types of busbar systems have their own advantages and disadvantages. Choosing a suitable busbar structure can improve the reliability, flexibility and safety of the power system.