The basic operational principle of the series active power filter, when compensating the voltage type load, is analyzed through its system configuration. On the basis of this, the control strategies for obtaining its reference voltage, one of pivotal technolog, are discussed. Corresponding control circuits are designed, including the control strategies of detecting the source current and load voltage. The compensation effects of the series active power filter adopting the two different control strategies, on the voltage type load are investigated by final experiments.