229 results about "Thermal network" patented technology

The invention provides a comprehensive energy system multi-objective operation optimization method considering an electric heating gas network. The comprehensive energy system multi-objective operation optimization method comprises the steps that a comprehensive energy system sub-network model comprising a natural gas network, a power network and a thermal network is established according to the obtained comprehensive energy system main information; then, an integrated energy system typical coupling equipment model comprising an electric boiler, a combined heat and power system, an afterburning type biomass boiler and a solar heat collector is established; secondly, on the basis of the maximization of the economic benefits and the environmental benefits, a multi-objective operation optimization model is established, and the comprehensive energy system operation constraint conditions including the coupling equipment operation constraints, the tie line power exchange constraints and thesub-network operation constraints, are set; and finally, the multi-objective operation optimization model is solved, and the main information of the comprehensive energy system is outputted. Accordingto the method, the effectiveness of the model and the method on the comprehensive energy system operation optimization is verified through the example analysis, and the reference can be provided forthe multi-objective operation optimization of the comprehensive energy system.

The invention discloses a battery thermal-runaway prediction method based on a thermal-resistance network model. According to the method, battery single-bodies in a large battery pack are simplified into thermal network nodes, convection, thermal-conduction and radiation processes in a battery pack system are simplified into thermal resistance, and a circuit solving method is utilized to realize fast calculation of battery pack thermal-transfer processes. In addition, different cooling manners are simplified into corresponding thermal-resistance modules to be embedded into a battery pack thermal-resistance network, and effectiveness of the cooling manners on thermal-runaway protection can be evaluated. A thermal-runaway prediction process includes: establishing a single-body thermal-resistance network on the basis of thermal-transfer feature parameters of the battery single-bodies; calculating battery steady-state thermal-generation quantity, setting corresponding thermal-management schemes, and obtaining battery single-body thermal-generation features of a thermal-runaway process through experiment; establishing the battery pack thermal-resistance network; giving a thermal-runawayoccurrence position, and setting a normal battery thermal-runaway temperature lower-limit; and recording predicted battery pack damage progress and damage time, and assessing protection effects of the different thermal-management measures.

A controller of a power converter has: an average loss calculator (202) calculating an average loss in a semiconductor device; and a partial temperature variation estimation part (204), while regarding the semiconductor device as a thermal network including at least one combination of a thermal resistance and a thermal time constant, estimating a partial temperature variation of the combination from a loss in the semiconductor device and the combination of the thermal resistance and the thermal time constant. The partial temperature variation estimation part (204) estimates an average temperature from the loss, the thermal resistance, and the thermal time constant; extracts a pulsation envelope temperature exceeding the maximum value of a pulsation temperature dependent on the average loss and the pulsation frequency; and estimates a temperature variation in the semiconductor device by adding the average temperature and the pulsation envelope temperature.

The invention discloses an IGBT module health state monitoring method based on a natural frequency of a thermal network. The IGBT module health state monitoring method comprises the steps of: establishing a fourth-order equivalent Cauer thermal network model according to physical performance parameters of an IGBT module and a radiator; establishing a mapping relationship between the natural frequency of the thermal network and parameters of each order in the thermal network model according to an order-of-magnitude difference between the thermal parameters of each order; fitting a measured junction temperature cooling curve of the IGBT module to obtain the natural frequency of the thermal network; and monitoring a health state of the IGBT module according to the natural frequency. The IGBTmodule health state monitoring method can monitor the aging degree of the IGBT module under the condition that the power loss of the IGBT module is not measured.

A method for predicting the junction temperature of three-dimensional resistance-capacitance thermal network of asymmetric half-bridge power convert features that the junction temperature of the three-dimensional resistance-capacitance thermal network is predicted by using the junction temperature of the three-dimensional resistance-capacitance thermal network of asymmetric half-bridge power converter. In this method, the junction temperature of power devices in asymmetric half-bridge power converters under different loads is predicted. The junction temperature coupling and boundary conditiondecoupling are taken into account, and a three-dimensional resistance-capacitance thermal network model is established to realize the effective junction temperature prediction of power devices. Firstly, the transient loss distributions under different load conditions are obtained in asymmetric half-bridge power converters. Secondly, the finite element model of asymmetric half-bridge power converter is established, and the coupling thermal impedance and boundary decoupling thermal impedance are extracted according to the finite element thermal stress simulation with the transient loss as the input of thermal load. Then, the expressions of coupled thermal impedance and heat dissipation boundary conditions are obtained by means of electrothermal analogy theory and curve fitting. Finally, a three-dimensional resistive-capacitive thermal network model is constructed to predict the junction temperature of the power device by using the controlled voltage source to represent the thermal coupling impedance relationship and the sub-radiator thermal impedance to represent the different thermal boundary conditions.