# Game Approach to HDR-TS-PV Hybrid Power System Dispatching
## 2 \(Hdr\)-\(Ts\)-\(PV\) Hybrid Power System Architecture
### Operating Characteristics of HDR Power Station in Hybrid Power System  
The _HDR_ power station, as shown in Figure 2, is composed of a geothermal mining cycle and _ORC_ generator, coupled with a heater. The geothermal mining cycle consists of underground _HDR_ fracture channels, a production well, a reinjection well, a circulating pump, and the heater. The brine is driven by the circulating pump from the reinjection well into the underground _HDR_ fracture channels to absorb geothermal energy, then from the production well into the heater to release the heat and re-enter the reinjection well.  
The _ORC_ generator includes the heater, a recuperator, a turbine, a condenser, a generator, and a pump. The liquid organic working fluid butane is driven by the pump to enter the heater for absorbing the heat released by the brine. The butane with the saturated vapor state then enters the turbine to expand and convert heat into mechanical energy. The residual energy still contained in the exhaust butane gas is transferred to the low-temperature liquid butane through the recuperator. The exhaust butane gas finally condenses into the low-temperature liquid butane in the condenser and then enters the next cycle again. A more detailed discussion of the _ORC_ could be found in [38].  
Several days are required for the _HDR_ power station to establish a stable geothermal mining cycle, and a similar period is required to adjust the geothermal working fluid pressure and flow rate, and the fluid used is usually brine. Therefore, compared to thermal power plants, the power ramp rate of conventional _HDR_ power stations is low, and frequent start and stop cannot be achieved. In the actual operation, the _HDR_ power station consistently maintains its geothermal mining cycle by alternately configuring two circulating pumps. This feature further urges the _ORC_ generators to continuously generate electricity in order to fully exploit the geothermal energy for higher economic benefits. The continuous power generation model of a conventional _HDR_ power station [12] is  
\[P_{HC}^{t}=\eta_{P}m_{r}^{t}c_{pr}(T_{HDR}-T_{Well}) \tag{1}\]  
where \(P_{HC}^{t}\) represents the output power, \(m_{r}^{t}\) is the mass flow of brine, \(c_{pr}\) is the specific heat capacity of brine, and \(\eta_{P}\) is the _ORC_ generator's efficiency. \(T_{HDR}\) and \(T_{Well}\) represent the outlet temperature of the production well and the temperature of the reinjection well, respectively.  
It should be noted that under the hybrid power system architecture shown in Figure 1, part of the continuous geothermal energy generated by the geothermal mining cycle can be stored in the thermal energy storage tank through the _TESE_ so that the geothermal energy flow is decoupled from the electrical energy flow of the _ORC_ generator. Therefore, the _HDR_ power station can fully utilize the fast adjustment speed and wide range of operating  
Figure 2: Structure chart of the hot dry rock (_HDR_) power station.  
conditions of the \(ORC\) generator to provide reserves without losing geothermal energy. The flexible power generation model of the \(HDR\) power station can be expressed as follows:  
\[m_{\alpha}^{t}+m_{\beta}^{t}=m_{r}^{t}, \tag{2}\]  
\[Q_{\beta}^{t}=m_{\beta}^{t}c_{pr}(T_{HDR}-T_{\beta}), \tag{3}\]  
\[P_{Hf}^{t}=\eta_{P}m_{\alpha}^{t}c_{pr}(T_{HDR}-T_{Well}), \tag{4}\]  
where Equation (2) represents the model of the brine distribution, \(m_{\alpha}^{t}\) represents the mass of the brine used for power generation, and \(m_{\beta}^{t}\) represents the brine used for thermal energy storage. \(Q_{\beta}^{t}\) is the thermal power input to the TESE in Equation (3), and \(T_{\beta}\) represents the waste heat temperature of the brine after TESE. The output power of the \(HDR\) power station can then be described by Equation (4), where, \(P_{Hf}^{t}\) represents the output power.