The PCS pitch system, as shown in the figure below, includes one Center Box (central cabinet) and three Axis Boxes (blade pitch drive control cabinets). Compared to pitch systems from other companies, the central cabinet design of PCS is relatively simple. It does not use a PLC to implement control functions but only performs the distribution of 400V power, UPS power, and CANopen signal lines. The main control cabinet layout includes components such as the main switch, fuses, filters, lightning protection, and any additional components that the customer may require.

The three blade pitch drive control cabinets of the system include functions such as backup safety systems, drive control, battery management, and diagnostic capabilities, which are implemented through their respective modules*. Compared to other pitch systems, it offers greater redundancy and superior reliability.

Emerson 1C31234G01 Controller Emerson Integrated blades are lower in cost compared to modular ones. However, modular systems offer advantages such as flexible functional expansion, ease of maintenance (module replacement), and straightforward fault diagnosis. The structural form of the PLC should be selected based on actual needs. The allocation of input/output points generally corresponds one-to-one with input signals and output controls. After allocation, each input signal and output signal is assigned a channel and contact number according to the system configuration, i.e., numbered. In rare cases, two signals may share one input point. In such cases, the signals should be wired according to their logical relationship (e.g., connecting two contacts in series or parallel) before being connected to the input point. (1) Determine the I/O channel range: Different models of PLCs have different input/output channel ranges. The corresponding programming manual for the selected PLC model must be consulted to avoid mismatching. It is essential to refer to the relevant operation manual. (2) Internal auxiliary relays: Internal auxiliary relays do not output externally and cannot be directly connected to external devices. Instead, they are used for data storage or data processing when controlling other relays, timers, or counters.