The dynamic braking of induction motors is investigated with particular emphasis on the use o-f zero-sequence connections. The braking performance using both AC and DC supplies is compared. A mathematical model is developed to predict both the transient and steady-state zero-sequence braking performance. To ensure accurate calculations, a model is constructed to allow for the variation of secondary parameters with frequency due to the skin effect. A method for determining the zero-sequence parameters using locked rotor variable frequency data is presented. To measure the transient acceleration torque of the machine, a rotational accelerometer is developed from a small single-phase induction motor. Good correlation between measured and calculated results is achieved during switching transients for both current and torque . The zero-sequence braking performance is analysed quantitatively and found to be an attractive alternative. When an AC zero-sequence supply is used, braking is suited to situations where it is not essential to brake to a standstill and minimising cost is an important consideration. With a DC zero-sequence supply, the braking is effective down to zero speed and worthy of serious consideration in situations where DC injection braking is currently used.