## 4 Case Study  
### Case Description  
#### 4.1.1 ME-VPP of Hongfeng Eco-Town in Southwestern China  
Hongfeng Eco-town is a demonstration base operated by Guizhou Power Grid Corporation for multi-energy coordinative dispatch. As shown in Figure 5, it is located on the shore of Hongfeng Lake, which is 27 km from Guiyang, a capital city of Southwestern China. Covering a terrain of 3.35 km\({}^{2}\), Hongfeng Eco-town is equipped with a hydropower unit, a CCHP, three wind turbines, three photovoltaic (PV) arrays, two battery blocks (lithium iron phosphate), and an electric vehicle (EV) charging station. The network structure is shown in Figure 6 and parameters are listed in Table 1[9].  
Figure 4: Scheme of improved multi-objective particle swarm optimization (MOPSO).  
Figure 5: Hongfeng Eco-town on Google Maps: (**a**) geographical location; (**b**) satellite image.  
Figure 6: One-line diagram of ME-VPP in Hongfeng Eco-town.  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Bus**} & \multirow{2}{*}{**Facilities**} & \multicolumn{2}{c}{**Power Source**} & \multicolumn{1}{c}{**Power Load**} \\ \cline{3-5}  & & **Lower Limit (MW)** & **Upper Limit (MW)** & **Nominal (MW)** \\ \hline
1 & Main grid & \(-10\) & \(10\) & - \\
2 & EV charging station \& load & \(-0.43\) & \(0.43\) & \(1.12\) \\
3 & load & - & - & \(0.52\) \\
4 & PV array \& load & 0 & \(0.61\) & \(1.41\) \\
5 & load & - & - & \(0.37\) \\
6 & load & - & - & \(4.35\) \\
7 & CCHP & 0 & 2.86 & - \\
8 & Hydropower unit & 0 & 10 & - \\
9 & Battery block \& load & \(-0.43\) & \(0.43\) & \(1.02\) \\
10 & PV array\& load & 0 & \(0.61\) & \(1.96\) \\
11 & Load & - & - & \(1.91\) \\
12 & Load & - & - & \(2.65\) \\
13 & PV array & 0 & 0.61 & - \\
14 & Battery block & \(-0.43\) & \(0.43\) & - \\
15 & Wind turbine \& load & 0 & \(0.69\) & \(4.22\) \\
16 & Load & - & - & \(1.55\) \\
17 & Load & - & - & \(3.97\) \\
18 & Wind turbine & 0 & 0.69 & - \\
19 & Wind turbine \& load & 0 & \(0.69\) & \(0.25\) \\ \hline \hline \end{tabular}
\end{table}
Table 1: Bus parameters of ME-VPP in Hongfeng Eco-town.  
Without loss of generality, we randomly select certain day in Eco-town as a typical day for research. The electrical load, power output of wind turbines and photovoltaic panels are drawn as Figure 7. As a multi-energy carrier system, CCHP is researched by annual operating model generally [25; 29], since heat load mainly exists in winter and cooling load mainly exists in summer. Few cooling loads in winter and heat loads in summer could be supplied by electrical devices that require electrical load. Three types of load in a typical day are depicted in Figure 8.  
In order to calculate the cost of environmental governance, some pollutant emissions coefficient and cost about China are searched and listed as Table 2. Appropriate adjustments have been made according to the energy particularity of Guizhou province. The row of \(\mu\) records environmental governance tariffs of CCHP, storage devices, and the main grid, which are \(\mu_{\text{c}}\), \(\mu_{\text{s}}\), and \(\mu_{\text{g}}\), respectively.  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Pollutant Emissions**} & \multicolumn{2}{c}{**Coefficient of Emission kg/MW-h)**} & \multirow{2}{*}{**Goverance Tariff**} \\ \cline{2-2} \cline{4-5}  & **CCHP** & **Storage Devices** & **Main Grid** & **(CNY/kg)** \\ \hline CO\({}_{2}\) & 408.6 & 25.8 & 778.5 & 0.210 \\ SO\({}_{2}\) & 0.056 & 0.0003 & 0.397 & 14.843 \\ NOx\({}_{\text{s}}\) & 0.1500 & 0.0075 & 0.3410 & 62.964 \\ \hline - & \multicolumn{2}{c}{**Goverance Tariff (CNY/kW-h)**} & \multicolumn{2}{c}{-} \\ \hline \(\mu\) & 96.08 & 5.89 & 190.85 & - \\ \hline \hline \end{tabular}
\end{table}
Table 2: Pollutant emissions coefficient and environmental governance tariff.  
Figure 8: Three types of load in a typical day.  
Figure 7: Profiles of wind power, solar power and electrical load in a typical day.