The invention provides a control method for a low-
voltage static var generator based on a
voltage space vector, and belongs to the control methods for the low-
voltage static var generators. The method comprises the steps that an actual output current and command current of a STATCOM are detected according to a STATCOM detection unit, an error
current vector delta is determined, and a STATCOM
mathematical model is combined to determine a constraint condition of an equivalent error voltage; the STATCOM adopts a double
hysteresis control method, the width of an
inner loop of a
hysteresis loop is I<w1>, the width of outer outer loop of the
hysteresis loop is I<w0>, when ||
delta|| is grater than I<w0>, the error
current vector delta is determined to be at the outer loop, and the current
inner loop adopts an
internal model controller to accurately calculate an output voltage u<c>* of the STATCOM; when the ||delta|| is greater than I<w1> and less than I<w0>, the error
current vector delta is determined to be at the
inner loop, a
system is in a
stable state, and a
voltage vector method is adopted to control the STATCOM to output a fundamental
voltage vector in a sampling period; when the ||delta|| is less than I<w1>, the error current is located in a dead zone, the on-off state remains unchanged, and the stability of the
system is improved. A voltage
space vector modulation method and the
hysteresis control method are combined, the compensation precision is high, the response speed is fast, the
switching frequency is low, and the performance requirements of the STATCOM are met.