Preface

As an important equipment in the field of modern energy conversion and transmission, the careful design and reasonable composition of the inverter-boost integrated silo are the key to achieving efficient and stable operation.

The inverter-boost integrated cabin, as the name suggests, integrates the two key functions of PCS and boost into a compact and efficient cabin. This integrated design brings many significant advantages. The following takes a 2MW inverter-boost integrated silo as an example to analyze the internal composition and design.

1. Composition of the inverter-boost integrated warehouse The inverter-boost integrated warehouse adopts a standard container design, which is flexible in deployment and convenient for operation and maintenance. It can generally adapt to 500kW and 630kW energy storage converter PCS. The built-in transformer can adapt to voltage levels of 35kV and below, and supports local and remote monitoring.

The inverter-boost integrated warehouse integrates energy storage converters, boost transformers, high-voltage ring network cabinets, low-voltage distribution boxes and other equipment in one container. It has a high degree of integration, reduces the difficulty of on-site construction, and is easy to transport, install, use and maintain.

It has built-in emergency lighting system, fire protection system, access control system, and heat dissipation system. There are fireproof partitions inside the box, ventilation openings on both sides of the box, and heat dissipation ducts specially designed for PCS, which can effectively ensure the normal operation and safety of the equipment inside the boost integrated warehouse.

2. Design of the main circuit of the inverter-boost integrated warehouse From the perspective of space utilization, the integrated cabin greatly saves the floor space required for equipment installation. Compared with traditional distributed inverter and boost equipment, it integrates complex circuits and components into a cabin, which not only reduces the connection lines between equipment and reduces line losses, but also makes the entire system more concise and beautiful, and is easy to layout in a limited space.

The 2 MW containerized energy storage boost transformer system mainly consists of a container body, four 500kW energy storage bidirectional converters, a 1250 kVA, 10 kV/0.38 kV transformer, a 1250 kVA, 10 kV/0.38 kV transformer, a 250 kVA, 10kV/0.38 kV isolation transformer, and supporting high-voltage switch cabinets, low-voltage distribution cabinets, and local monitoring system cabinets.

Two energy storage bidirectional converters are used as a group. The DC side of each group of energy storage bidirectional converters is connected to the energy storage system, and the AC side is connected to the secondary side of the 1250 kVA, 10 kV/0.38 kV transformer. The high voltage side of two 1250kVA transformers are connected in parallel to a 10kV high voltage switchgear. The total output of the system is 2MW, 10 kV three-phase AC, and energy can flow in both directions on the DC side and the AC side.

3. The high-voltage side of the high-voltage system uses a 10kV high-voltage switch cabinet to access the park's 10kV busbar, with one in and two out. One way is to supply power to two 1250 kVA transformers in parallel through a high-voltage circuit breaker, and the other way is to supply power to a 250kVA isolation transformer through a load isolation switch plus a fuse.

The ring network cabinet is equipped with an isolation switch, a fuse, a circuit breaker, a lightning protection device, a live indication device, a fault indication device, a current transformer, and a comprehensive protection device. The comprehensive protection device controls the circuit breaker tripping by monitoring system parameters to achieve local and remote operation.

4. Local monitoring system The local monitoring system is installed in the local monitoring cabinet, with a programmable controller as the core, and is used to realize the status acquisition and system communication of transformers, high and low voltage switches, converters, fire equipment, air conditioners, lighting equipment, security equipment, etc. It has a human-computer interaction interface to display the status and parameters of the 2 MW container-type energy storage booster system.

5. Energy Storage Bidirectional Converter The energy storage bidirectional converter is the core component and is an important guarantee for achieving efficient, stable, safe and reliable operation of the 2 MW containerized energy storage boost converter system and maximizing the utilization of wind and solar energy. Combined with the on-site use environment and actual operation requirements, the energy storage bidirectional converter is designed to achieve grid-connected and off-grid operation functions.

The energy storage bidirectional converter is connected to the large power grid for a long time. The battery system is charged when the park load is small, and the battery is discharged when the park load is large. The energy storage bidirectional converter is required to have the function of grid-connected operation, realize independent decoupling control of active power and reactive power, and be able to coordinate with the superior monitoring system to realize various applications of the power grid system in the park.