4.1 Introduction

This chapter examines the effect of wind generation on the transmission and distribution network to which it is connected. Topics include control of voltage and power flows, the quality of supply and the protection of plant and equipment. The principles underlying network development in the face of increasing wind generation are reviewed. The perspective is that of a network operator sympathetic to wind power development. It will be seen that wind power capacity may exceed strict technical limits, provided wind power operators are prepared to accept occasional energy curtailment. Achievement of this ideal balance will require enlightened negotiation between the two parties.

There are eight basic issues to be considered by network and wind farm planners. These aspects of wind farm connection are listed below, with the corresponding sections.

1. Wind farm starting (Section 4.2)

2. Network voltage management (Section 4.3)

3. Thermal/active power management (Section 4.4)

4. Network power quality management (Section 4.5)

5. Transient system performance (Section 4.6)

6. Fault level issues (Section 4.7)

7. Information (Section 4.8)

8. Protection (Section 4.9)

4.2 Wind Farm Starting

Fixed-speed wind turbine generators (WTGs) must be rotated within 1 2 per cent of their electrical synchronous speed. Acceleration from rest is generally achieved by using the kinetic energy in the wind to drive the turbine and electrically isolated generator close to synchronous speed, at which point the circuit breaker with the grid is closed. It is common to use an anti-paralleling thyristor soft start arrangement to reduce the fluxing...