With the rapid development of renewable energy power, the task of peak load regulation and frequency control for the power grid is very severe. Using the heat storage of the heat supply unit to take part in peak load regulation and frequency control is imperative. On the basis of the simplified nonlinear dynamic model of the typical heat supply unit, the model was linearized under different operation point conditions. The control performances of three typical coordinated control system modes were compared under the typical operation point conditions. The experiment results show that if the parameters of the controller are set well on any operation point, the control system of heat supply unit can adapt the normal variation of the load around the operation point, which can provide support for utilization of the heat storage of the heat supply unit.