This paper investigates gain scheduling control strategy for ORC (organic Rankine cycle) based WHECSs (waste heat energy conversion systems) over a wide range of operating conditions. A low order physical model is first developed for ORC based WHECSs. Then the nonlinear dynamics of the WHECS are formulated by an affine LPV (linear parameter varying) system. The generated offline LPV system is characterized by dependence on the mass flow rate and temperature of the waste heat at the inlet of the evaporator. The gain scheduling controller based on the LPV model ensures that the WHECS can obtain satisfactory performance over a wide range operating region. The simulation results demonstrate the effectiveness of the proposed controller. (C) 2016 Elsevier Ltd. All rights reserved.