To satisfy reactive power and voltage control requirements of grid-connected photovoltaic power station, setting the qualified voltage and power factor at the PCC as the optimal control objective, strategies based on nine-zone diagram for reactive power and voltage control are proposed to PQ-type and PV-type photovoltaic power stations. Equivalent models of PQ-type and PV-type photovoltaic power stations are built and the flowcharts for reactive power and voltage control strategies are presented. Based on the typical dynamic changes of photovoltaic power station output and load, a 110 kV system with large-scale photovoltaic power station for reactive power and voltage control is given and the results of simulation show that the proposed strategies are effective and practical.